Sentinel locomotives & railcars

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The introduction of diesel traction brought the railways into close contact with development work for road vehicles and marine craft. This was in contrast to steam where development tended to be isolated, except for a few experiments with turbines or condensers which were usually related to naval advances. The Sentinel products were major exceptions as they formed an extension of the Company's interest in steam road vehicles.
The Sentinel railcars and locomotives incorporated small, vertical water-tube boilers which powered multiple-cylinder, high speed enclosed engines. The cylinders were actuated by poppet valves and the final drive was either by chain or cardan shaft. A few units were constructed with Doble, high performance boilers. Hughes & Thomas is the key reference where it is noted that the chain drive obviated pounding and nosing. The company produced some excellent promotional literature at its London Office: some of this is listed below. Lowe estimated that 7000 of the highly distinctive engines were produced, but the majority were used in road vehicles. Miles Macnair has returned to the Sentinel story in Backtrack, 2020, 34, 164 .

There is a section entitled professional papers which also includes an official accident report

Company literature

The "Sentinel" Waggon Works Ltd., London.
"Sentinel-Cammell" gear driven rail cars. London, Sentinel, 2nd ed., 1931. 83 p. + 3 folding plates. 42 illustration (including 1 colour.), 23 diagrams, 8 plans, table.
"Sentinel-Cammell" patent light railway vehicles. London, Sentinel, 1932. 168 p. + 2 folding plates. 74 illustration, 32 diagrams, 16 tables, 16 plans.
Sentinel patent locomotives. London, Sentinel, 1927. 72 p. + folding plate. 50 illustration, 23 diagrams, 9 tables, 3 plans.
Some railway problems of to-day and their solution. London, Sentinel, 1927. 64 p. + folding plate. 25 illustration, 10 diagrams, 5 tables.
Each work described above is a combination of detailed catalogue and economic assessment. The catalogue sets out the specification for each product in detail. Reviewed Locomotive Mag., 1927, 33 , 238.


Light traffic work with the "Sentinel" locomotive. Loco. Rly Carr.Wagon Rev., 1927, 33, 281-2.
Narrow gauge back-to-back locomotive (described as articulated); also non-articulated locomotives for narrow gauge passenger-carrying lines in India and for the Egyptian Nile Delta Railway.

W.J.K. Davies. Light railway notes. Rly Wld, 1963, 24, 232-4.
Sentinel articulateds for narrow gauge.
3ft gauge Sentinel WN 6412/1926 ordered by Kettering Iron & Coal Co. Another, incorporating modifications (WN 7238/1927) was supplied to W.A. Smith's sugar plantations in South Africa and was more successful and in 1928 WN 6412 was returned to Sentinel for modification, after which it worked on the Thorpe Malsor branch until it closed.  

Locomotives: 0-6-0T

1956 for heavy industrial use

"Sentinel" oil-fired locomotive. Locomotive Mag., 1956, 62 161-3. illustratiion, diagram (side, front & rear elevations, plan)

Locomotives 0-4-0T
Several contemporary references are listed below. sub-division has not been attempted as a number of parameters could have been used, none being applicable throughout. Lowe notes that approximately 850 steam locomotives were constructed between 1923 and 1957

A GEARED shunting locomotive. Engineer, 1925, 139, 432-4; 436. 6 illustration, 6 diagrams, plan.
Includes detailed sectionalized diagrams.
"SENTINEL" geared locomotive. Loco. Rly Carr.Wagon Rev., 1950, 56, 172-3. ilIus.
This series was not purchased by any British main-line system, but it does show that the type was available after WW2..

For specific railways

GSR (Ireland)
SENTINEL locomotive No. 1, Great Southern Railways, Ireland. Rly Mag., 1928, 62, 134. illustration
Illustration—no text: further information under GSR M1 Class..

SENTINEL locomotive for Clee Hill, L.M. & S. Ry.. Loco. Rly Carr. Wagon Rev., 1932, 38, 63. illustration
SENTINEL locomotives, L.M.S.R.. Loco. Rly Carr. Wagon Rev., 1930, 36, 229. illustration
Nos. 7180-7183 : two-speed 100 h.p. type: No. 7163 illustrated..

Later Doble-type locomotive

Crabtree, J.A. The automatic control of small boilers. Trans Newcomen Soc., 1970, 43, 93-112.
Includes Doble's developments, mainly for automobiles, but also for Sentinel lorries (trucks), and for the Sentinel locomotive for LMS and railcar for Southern Railway..
Comyns-Carr, C A. The application of the Doble steam power concept to coal-fuelled rail traction. Trans. Newcomen Soc., 1997, 69, 177-99. Discussion: 200-3

Y1 and Y3 (latter 2-speed)
The RCTS Locomotives of the LNER. Part 9B: In March 1928 the L.N.E.R. borrowed a Sentinel locomotive which had been built in November 1926 and loaned to the L.M.S.R. at Newton Heath. It was specially lightened by removing the ballast weights to enable it to work around the Victoria Dock at Hull. It was purchased in January 1929 and became class Yl No. 19. Another Sentinel locomotive (Works No. 6776) was also loaned to the L.N.E.R. in 1928. This had four cylinders and achieved notoriety by setting fire to the shed roof at Scarborough. It was not purchased by the L.N.E.R.
The Sentinels obtained in 1930 were instead of a further twenty class J72 0-6-0T's originally planned to be built at Darlington, the Sentinels being regarded as more economical. In fact, at a meeting held on 3rd October 1934, Gresley was still emphasising the light coal consumption of the Sentinels which, over the previous three or four years, was approximately 15 lb. per mile. Details were given of more advanced designs prepared by the Sentinel Co. and the Locomotive Running Superintendents were told that trials should be conducted with them when they became available. They were asked to bear this in mind when making their final recommendations for the 1935 building programme. However, in the event, these advanced designs did not give the required efficiency and so were never purchased by the L.N.E.R. Between 1929 and 1931 forty-two more Sentinels were obtained for the Running Department, comprising twelve Y1s for the N.E. Area and thirty Y3s which were shared between the Southern (20) and N.E. (10) Areas. In addition, a Y1(No. 45) was obtained iin 1930 for Departmental use at York (Leeman Road) and in 1933 No. 59 fou use at Darlingtom (Geneva) Permanent Way Yard. A table shows purchases and Sentinel Works Numbers. .
Sentinel Waggon Works of Shrewsbury had developed the design from their widely-used steam road lorries using the same type of vertical boiler and high-speed engine with chain drive to the wheels. A noticeable feature during the test runs was the steady drawbar pull attainable over a distance. With the rotary motion imparted to the wheels by the chain drive there was an absence of pounding and a reduced tendency to slip compared with a normal reciprocating locomotive. The Sentinel seemed ideal for use on light branch lines or in yards where the track was not up to standard. In September 1925 the L.N.E.R. purchased a similar locomotive, No. 8400, for Departmental duties at Lowestoft harbour. It was given the classification YI, not used hitherto. Four more were purchased in 1926 for Departmental use. The first three of these were required for service at Boston (Hall Hills) Sleeper Depot, Peterborough Engineer's Department and Doncaster (Carr) Wagon Works, but were not taken into stock until 1927. They were un-numbered at first, but in April 1930 they became Nos. 4801/2/3 respectively. The fourth of these locomotives was numbered 8401 and sent to Lowestoft (North Beach) Sleeper Depot. Two others were obtained for Departmental use in 1927, No. 8402 for Temple Mills Wagon Works, Stratford, and No. 44 for Faverdale Wagon Works, Darlington. Also in 1927 four Sentinels were purchased for the Running Department.
The "engine" was centrally placed over the wheelbase and for this reason the makers referred to the single-speed design as type C.E., i.e. centre engine. The two-speed design was referred to as type C.E.D.G., i.e. centre engine double-geared.
The transmission consisted of strong roller chains which connected sprockets on the crank-shaft to a sprocket on each axle. On the single-speed Y1s the sprocket ratio was 11 :25, except on the 1929 locomotives numbered between 108 and 187 inclusive, in which it was changed to 9:25. The crankshaft operated at an optimum speed of 500 r.p.m. whilst the maximum advisable speed, according to the makers, was about 600 r.p.m. The latter was equivalent to a wheel speed of about 21 m.p.h., or 19 m.p.h. with the altered sprocket ratio, though the normal working speed hauling a load was about half the rated maximum. The Y3s had a two-speed gearbox. Sliding pinions were located on the crankshaft, only one of which at a time meshed with a mating spur wheel on the countershaft which was immediately below it. The high-gear ratio was 18:71 and the low-gear 36:53. The low gear was suitable for shunting operations. High gear could be engaged by the simple operation of two small levers in the cab to enable the locomotive to work short goods trains or run light to shed, but the gears could only be changed whilst stationary. The sprocket ratio was 19:19, except on the locomotives delivered in 1931 in which it was 15:19, giving greater power.
The boiler was of vertical type, with an outer shell and inner firebox (or furnace), both of which were cylindrical. Coal was fed through a chute in the top and fell down on to the grate, which had a slightly conical centre so that the fuel was distributed to the outer circumference of the firebox. The firebox tapered outwards slightly from top to bottom to facilitate its easy withdrawal through the base of the outer shell after the superheater coil was taken out from the top. The firebox, complete with water tubes, was in fact removed periodically at the sheds for examination and the removal of scale, and exchanges were frequent. For instance, No. 18 had sixteen different fireboxes put into its original boiler between October 1932 and September 1942. On the earliest Y1s the diameter of the boiler at the top was 2ft. 8½tin. and the height was 4ft. 45/8in. The locomotives delivered new from December 1927, i.e. Nos. 79 and 9529 onwards, had larger boilers of similar pattern, 3ft. 1in. diameter at the top and 4ft. l013/32-in. high. The grate area was increased from 3.97 to 5.1 ft2. and the evaporative heating surface went up from 54.43 to 71.5 ft2.. The working pressure of both types of boiler was 275 lb. per sq. in. If the pressure fell below about 225 lb., power was lost and the engine ran "short of steam". The water tubes were arranged across the firebox in a spiral fashion set in corrugations, known as "leadings", in the firebox casing. There were three different lengths of tubes, which were therefore set at different angles both to assist in the circulation of the water and to provide a greater heating surface. On the small-boilered Yl s, for example, ten tubes were 2ft. 10tin. long and steeply inclined, ten were 2ft. 2tin. long and ten were 1ft. 6iin.long. Firebox construction was a complicated and specialised task, undertaken only by Galloways of Manchester. Sentinel simply assembled the parts and fitted the tubes.

Wisbech & Upwell Tramway locomotive (Y10)
This is one of the odder locomotive stories. The double ended locomotives were clearly intended for the Wisbech & Upwell Tramway (there is even a photograph of one with that appellation painted on it, but were equally obviously unsuccessful, and spent most of their lives on the Yarmouth street tramways (not the Corporation electric trams)

SENTINEL locomotives for the Wisbech & Upwell Tramway, L. & N.E. Ry.. Loco. Rly Carr. Wagon Rev., 1930, 36,401-2. illustration
L.N.E.R. class .Y10 : a two-speed double-ended tramway locomotive.

Fell, G. The Wisbech & Upwell Sentinels. Rly Wld, 1982, 43,. 521-3.
Ordered by the LNER in November 1929 the two Y10 class locomotives were intended for use on the Wisbech & Upwell Tramway where the former GER tram locomotives of LNER classes Y6 and J70 were the normal motive power. The 200hp locomotives were similar to two locomptives deleivered to the Somerset & Dorset Railway at about the same time but the LNER locomotives were fitted with skirts and cowcatchers for tramway operation (A works photograph shows one un-numbered locomotive with "Wisbech & Upwell Tramways" applied to the side skirts. One, or both locomotives were tested on the line between 11 June 1930 and  30 May 1931. Thereafter, the locomotives spent most of their time on the quays at Yarmouth, although 8404 was sent to Scotland in February 1934 and  was tested on the lines in Aberdeen docks and briefly at St Leonard's Yard in Edinburgh, but was back at Yarmouth in May. Reasons for the failure of the locomotives on the Wisbech & Upwell Tramway are discussed with reference to the appropriate volume of the RCTS History of locomotives of the LNER Part 9B and The Wisbech and Upwell Tramway by Gadsden, Whetmath and Stafford-Baker. There appear to be no photographs of the locomotives working at Wisbech, but are relatively common of working on the street lines in Yarmouth, although this article only includes view of them on shed at Vauxhall. See also Hutchings letter.
Goodyer, W. The Wisbech and Upwell Tramway. Rly Mag., 1937, 81, 82-7. 2 illustration, 2 maps.
Includes brief notes on the Sentinel tramway locomotives.
Gadsden, E.J.S., Whetmath, C.F.D. and Stafford-Baker, J. The Wisbech and Upwell Tramway. Teddington (Middx.), Branch Line Handbooks, 1966. 51 p. + front. + 2 folding plates. 30 illustration, 3 diagrams, 3 tables, 6 col. plans, 2 col. maps.
Includes notes and a sectionalized diagram of the Y10 class tram engines.
Hawkins, Chris and George Reeves. The Wisbech & Upwell Tramway. Bucklebury: Wild Swan, 1982. 56pp.
Includes 0-6-0T and 0-4-0T tram locomotives (latter restricted mainly to passenger traffic) and very brief mention of Y10 Sentinel tramway lcomotives.
[Hawkins, Chris] Some new notes: early trials and tribulations of running the Wisbech and Upwell Tramway. Br. Rlys. ill., 1995, 4, 530-45.
Mainly the difficulties faced with the local authorities. Includes a photograph of standard Sentinel locomotive No. 8401 with J70 tram locomotive on passenger train on 4 May 1927, (A. Garraway)
Hoole, K.. Sentinel locomotives. Rly Wld, 1958, 19, 235-40.
Surveys all the British main line railway Sentinel locomotives using the LNER purchaese as the yard stick. The LNER initial purchase was instigated by the acquisition of a Sentinel locomotive by the Derwent Valley Light Railway and the testing of this unit with the assistance of the LNER dynamometer car in May 1925. The LNER purchased similar units and classified these as class Y1 starting with Sentinel WN 6170/1925 which carried running number 8400. Many of this initial batch were employed aservice locomotives, such as No. 8401 at the Lowestoft sleeper depot and No. 44 at the Faverdale Wagon works. The locomotives had vertical water tube boilers operating at 275 psi and vertical cylinders. Firing was simple using a small domestic-sized shovel of the type used to feed domestic boilers. The boiler tubes were cleaned with steam which was blown up through the boiler and out of the chimney: the exhaust began black and tuned to white. The Y3 type differed in having two gear ratios and the means to switch between them. In other respects they were identical to the Y1 type: all were initially supplied for the running stock, but later some became service locomotives.Nos. 81 and 90 were fitted with vacuum ejectors and tested on passenger services between Seamer and Pickering in June 1928. Other locomotives were also fitted with vacuum ejectors. Steam and counter pressure braking were standard faetures. The Y10 double ended Sentinels, with two speed gearboxes were built for the Wisbech & Upwell Tramway, but were not successful and were transferred to Yarmouth to work on the quayside. They had foot-operated gongs, govenors to limit speed, skirts over the wheels and cow catchers. The LMS purchased four of the Y3 type (that is two-speed) and were given running numbers 7160-3. Two similar to the Y10, but with a single cab were built in 1929 for the Somerset & Dorset Joint Railway and were of restricted height. Sentinel WN 7587/9 were initially 101 and 192 but became LMS Nos. 7190-1. Sentinel WN 8593/1932 RN 7164 was s short wheelbase and light machine purchased for working at the Clee Hill quarry where it had to be hauled up and down a rope-worked incline. Sentinel WN 8805/1934 was built for the LMS and numbered 7192: it had a Doble boiler and was oil fired and was intended to be compared with early diesel shunters. It was withdrawn in 1943. The GWR owned a solitary Y1 type unit bought in 1926 numbered 13 which worked at the Park Royal Trading Estate, but was moved to Bridgwater in 1945. Illustrations: Y1 No. 8400; Y3 No. 117 at Hull Springhead on 21 June 1931; Y10 works photograph; Y3 No. 68169 in scrap yard at Doncaster on 17 July 1955: LMS No. 7164; LMS No. 7160; LMS 7192 with diesel No. 7051; and SDJR No. 104.
Hutchings, John M. The Wisbech and Upwell locomotives. Railway Wld, 1983, 44, 94.
Weitten in respponse to artcle by Fell notes ooperating problems and chain replacements.
Middlemass, Tom. Tram traction from Wisbech. Rly Mag., 1983, 129, (988) 315
Includes mention of ten months spent by Sentinel Y10. Written at the end of the Wisbech & Upwell Tramway.
{Mitchell, Vic, Smith, Keith} and Ingram, Andrew C. Branch line to Upwell. Midhurst: Middleton Press, 1995. 96pp.
It would appear that Andrew Ingham was the "real" author. Book is interesting for containing photograph (figure 27 taken by W. Whitworth) of Y10 Sentinel tram locomotive No. 8404 taken at Wisbech. Figures 27, 43 and 111 show experiments with Sentinel Y1 No. 8401 on passenger workings on 4 May 1927, both at Wisbech and at Upwell.
White, Malcolm. The Yarmouth train. 2005.
Some highly interesting photographs of the Y10 Sentinel locomotives working on the quayside tramway system, including one visiting the Lacon Brewery in 1936.


Hughes and Thomas quote tests on the LNER, which initially purchased one Sentinel GE. type on the maker's statement that it would save 50 per cent on coal, oil, stores, and maintenance. This was No 6170, new in January 1926. The results were so promising that three more were purchased in June, and by 1931 there were 55 Sentinel locomotives on the LNER.

An early official report of this railway stated:

The 100 H.P. 'Sentinel' engines are being used in replacement of ordinary steam engines employed on regular shunting work at Victoria Dock, Hull, at Pickering and at Goole. So far the engines are doing well and have enabled economies to be made which will be sufficient to write off the capital cost in less than two years. [Hughes & Thomas italics]

On another use for the Sentinels, shunting at wayside stations, the report said

On the pick-up working between Hull and Selby three freight train engines were employed, one working a pick-up from Hull to Brough and returning as a Class B through goods; another working a pick up from Selby to Brough and back, and the third engine proceeding light from Selby to Staddlethorpe, whence it worked a pick-up to Selby. By using a 'Sentinel' engine for intermediate shunting it was found possible to re-arrange the whole of the pick-up working so that in place of the three train turns previously mentioned there are now only two. . . . In this case and in that of a similar experiment on the Hull and Barnsley section the 'Sentinel' engine is also making economies in working costs sufficient to pay for itself within two years. [their italics again.]


The "Sentinel" Patent steam locomotive. Loco. Rly Carr. Wagon Rev., 32, 8-10. 3 illustration, diagram
NCC No.91.

Sentinel shunting locomotives, Somerset & Dorset Joint Railway. Loco. Rly Carr. Wagon Rev., 1929, 35, 142-4. illustration, 3 diagrams, plan.
Nos. 101 and 102. Includes sections.

Burgess, Neil. Somerset & Dorset Sentinels: a consideration of their place in LMS locomotive history. Backtrack, 2004, 18, 327-331.
S&DJR 0-4-0T Nos, 101 and 102 (BR 47190 and 47191). In some respects the purchase was rather surprising: Radstock in which the locomotives spent most of their time was an economic backwater at that time and the LMS was disposing many of its L&YR 0-4-0STs, some of which saw further service in industry. The Author suggests that the purchase may have reflected a more general evalution, especially as 7191 spent the three years, 1932-5, at Kettering and was at Highbridge from 1942-4 (KPJ but this may have reflected a shortage of . spare parts during WW2. The locomotives were 200hp with double engines and could be single-manned. John Edgington provided corrections to table (see page 443). Many references.
Thorley, W.G.F. A breath of steam. Vol. 1. London, 1975.
Page 95: Sentinel. One of the latter, No 7191, was allocated to Kettering to shunt in the large goods yard there and I [Thorley] was despatched more than once to fit a new firehole door to its vertical cross-tube boiler. My recollection is that the door was made from some alloy material which fractured rather easily and the door itself required to have a good seating on the firebox shell plate.

Other railways
[Super Sentinel locomotive performing passenger duties on the Shropshire & Montgomeryshire Light Railway]. Rly Mag., 1928, 62, 148. 2 illustration
New 20-ton steam llocomotive, Derwent Valley Ry. Locomotive Mag., 1925, 31, 187.
[TEST of a Sentinel locomotive on the Derwent Valley Light Railway]. Rly Mag., 1925, 57, 94.

Narrow gauge locomotives

This is not a very happy sub-division, but the article featured does show the highly distinctive WN 6412/1926 built for the 3ft gauge Kettering Iron & Coal Co. A table compiled from the Company's official records shows narrow gauge locomotives produced for United Kingdom customers. WN 7700 for the London Brick Company's clay pits at Stewartby clearly shows how the driver was shoe-horned into the low headroom 2ft 11in gauge locomotive.

Hutchings, John M. 'Sentinel' narrow gauge locomotives in the United Kingdom. Rly Bylines. 1998, 4, 14-22.

Ash clearing crane locomotives
According to Hughes & Thomas these were Works Numbers 8157 and 8565 of December 1919 and December 1931, respectively

"SENTINEL" crane locomotive, London & North Eastern Ry.. Loco. Rly Carr. Wagon Rev., 1930, 36, 183. illustration
"SENTINEL" crane locomotive, L.N.E.R.. Rly Mag., 1930, 67, 44. illustration
This "locomotive" was a self-propelled crane which was designed to clear ash pits at several locomotive depots.

Railway Correspondence & Travel Society.Locomotives of the LNER. Part 10A. Departmental stock, locomotive sheds, boiler and tender numbering. 1990?..
The self-propelling ash cranes are difficult to find, but are considered on page 19 under Scottish Area. There were two of these Sentinel Works Number 8157 (LNER 773044) and WN 8565 (773066). They were not regarded as locomotives yet were required to travel on running lines and were passed to run at 24 mile/h. The former worked at Eastfield and Parkhead in Glasgow where it was known as Stoorie Annie. The latter worked between Haymarket and St Margarets (but there were problems with track circuits), and later at Dundee and Thornton. Figures 53-5. The cranes were supplied by Henry J. Coles of Derby and had their own engine.

Railcars: (all had Cammell Laird bodywork)

1923 Original design with chain drive.
The first units were bought by the Jersey Railways (see also histories of Channel Islands railways). According to Hughes & Thomas Works Number 4863 of June 1923 and named The Pioneer was used on the 3ft 6in gauge Jersey Railways and Tramways between St Helier and St Aubins and Corbière. The passenger car was pivoted to the power bogie and the joint was filled with fireproof leather sides to form a flexible connection with a steel plate on the top. The wheels had rubber inserts to reduce noise and vibration. Coal consumption was 4lb/mile and water consumption 2½ gal./mile. The vehicle was noted for its smooth running. By June 1931 the unit had run 200,000 miles. WN 5759 was delivered in January 1924 and WN 5833 followed in March 1925. The Jersey Eastern Railway acquired a standard gauge railcar WN 5655 in March 1925. See also paper by Kelway-Bamber.

"Sentinel-Cammell " steam rail coach for use in Jersey. Rly Mag., 1923, 53, 224-5. illustration
"Sentinel-Cammell " steam rail coach in Jersey. Rly Mag., 1924, 54, 323-5. illustration
Results of nine months service.
STEAM rail motor coach, Jersey Railways & Tramways Company. Loco. RIy Carr. Wagon Rev., 1923, 29, 140-1. illustration, 2 diagrams
STEAM rail motor, No. 2, Jersey Railways & Tramways Company. Loco. Rly Carr. Wagon Rev., 1924, 30, 77-80. 4 illustration, 2 diagrams (including side elevation) 2 maps.
Includes sectionalized diagrams of the power unit plus results of the railcar in service.

Bonsor, N.R.P. The Railways of the Channel Islands. v.1. The Jersey Railway (J.R. & T.).1962. (Oakwood library of railway history, No. 58).
Includes notes on the early Sentinel railcars which operated on this 3 ft 6 in gauge railway.

LMS railcars
According to Hughes & Thomas these were WN 6177-88. They also cite Railway Gazette for "December" 1927 to note that all these vehicles were in service in Scotland, although originally envisaged for North Wales and Anglesey, the Wirral, the West Riding and the Southport area as well as Scotland.

[L.M.S.R. contract with the Sentinel Wagon Co. for 13 rail-cars]. Loco. Rly Carr. Wagon Rev., 1926, 32, 303.
Includes proposed spheres of activity.
[Tests of a Sentinel-Cammell railcar in the Derby District, L.M.S.R.]. Rly Mag., 1925, 56, 418-19. illustration

Stuart W. Rankin. LMS Sentinel railcar operations between 1926 and 1938. LMS Journal, 2011, (35), 47.
The response to this article was especially interesting for a letter from John Hutchings (Issue 37 p. 78) which explains how the boiler was replenished with water

LNER railcars
New steam rail auto-car, L. & N.E. Ry.. Loco. Rly Carr. Wagon Rev., 1927, 33, 149-50.
Includes details of test running in the Whitby area.
STEAM motor coach trials on the London and North Eastern Railway. Loco. Rly Carr. Wagon Rev., 1924, 30, 359.
Trials in the Whitby area.
TRIALS of Sentinel-Cammell rail auto-car. Loco. Rly Carr. Wagon Rev., 1926, 32, 270.
L.N.E.R. trials.

1928: 6-cylinder engine version with cardan shaft drive to a flexible bogie


A geared steam rail car. Engineer, 1928, 145, 551-4. 5 illustration, 3 diagrams, table.
Includes results of tests on the steeply graded lines in the Whitby area.
New Sentinel-Cammell geared rail car a new design for service on the L.N.E.R. Rly Engr. 1928, 49, 203-6. 7 illustration, 7 diagrams
Sentinel-Cammell gear-driven rail cars, L. & N.E. Ry.. Loco. Rly Carr. Wagon Rev., 1928, 34, 183-6. illustration, 3diagrams (including s.el.), plan.
Includes sectionalized diagrams.

Sentinel-Cammell geared rail coach, L.M. & S. Ry.. Loco. Rly Carr. Wagon Rev., 1930, 36, 368. illustration
Coach No. 4849.
[Sentinel-Cammell geared steam railcar for L.M.S.R.]. Rly Mag., 1930, 67, 250-1. illustration

200/250 h.p. articulated railcar with a Woolnough boiler, L.N.E.R. 2291 Phenomena.

L.N.E.R.articulated rail car. Rly Mag., 1931, 68. 73.

Test run : King's Cross to Cambridge and back.

Sentinel Cammell articulated steam rail car, L. & N.E. Ry.. Loco. Rly Carr. Wagon Rev., 1930, 36, 405-7. 3 illustration, diagram, plan.
A 200 horse-power steam rail coach. Engineer, 1930, 150, 594-5. illustration, 2 diagrams, plan.

Additional information

Lowe stated that the articulated unit used the Gresley patented system.

1932: Lightweight railbus
The Sentinel Co. produced a light rail bus for the Southern Railway which incorporated a 325 lb/in2 vertical boiler and a Doble-type engine. See also Holcroft Locomotive adventure. Vol. 2

A new Southern Railway railcar. Rly Mag., 1932, 71, 436-7.2 diagrams, plan, map.
"Sentinel-Cammell steam rail-bus for the Southern Ry.. Loco. Rly Carr. Wagon Rev., 1933, 39, 145-6. illustration
[Sentinel Cammell steam rail bus for the S.R.] Rly Mag., 1933, 72, 383-4. illustration
Sentinel railcar on Westerham Branch. Rly Gaz., 1936, 64, 577.

Holcroft, H. Locomotive adventure. v.2. Running experiences. 1965.
Chap. XV (pp. 287-302) This is an exhaustive account of the Southern Railway railbus which included its delivery along the West Coast Mainline
Crabtree, J.A. The automatic control of small boilers. Trans Newcomen Soc., 1970, 43, 93-112.
Includes Doble's developments, mainly for automobiles, but also for Sentinel lorries (trucks), and for the Sentinel locomotive for LMS and railcar for Southern Railway..

Professional papers

Ablett, N.L. Rail cars. J. rec. Trans. jr Instn Engrs, 1942/43, 53, 223-8.
Economics and engineering: includes the Sentinel type.
Anderson, E.P. Report on the accident that occurred on the 26th July, 1929, through a steam coach colliding with the buffer stops in No. 5 platform road at Waverley Station, Edinburgh. Ministry of Transport: Railway accidents which occurred during the three months ending 30th September, 1929. London, HMSO, 1930.
No.31 Flower of Yarrow (a 6-cylinder 100 h.p. type) was involved in a minor accident which led to criticism of the brake gear.
Ballan, L. Light rail units for passenger and freight work. Loco. Rly Carr. Wagon Rev., 1929, 35, 79-82; 120-1.
Abstract of a paper presented to the Newcastle and Sunderland Railway Lecture and Debating Society. It gives details of operating experience with both the Sentinel and Clayton units on the LNER.
Beaumont, J.W. Some suggestions on steam locomotive design. J. Instn Loco. Engrs, 1936, 26 ,417-24. Disc.: 424-37. (Paper No. 355).
Includes details of the LMS Doble boiler Sentinel locomotive.
Beaumont, J.W. The working of light traffic on railways and the "Sentinel" engine. J. Instn Loco. Engrs, 1927, 17. 30-53. Disc. : 53-9; 273-80 (Paper No. 209).
A description of the Sentinel locomotives and railcars, plus experience gained from service on the LNER.
Comyns-Carr. The application of the Doble steam power concept to coal-fuelled rail traction. Trans. Newcomen Soc., 1997, 69, 177.
This includes discussion of the LMS Sentinel locomotive which had a liquid-fuelled flash boiler and was constructed to act as a comparitor to the internal combustion locotives being aquired in the late 1930s. It also includes the railbus acquired by the Southern, and the metre gauge locomotive for Colombia.
Kelway-Bamber, H. Modern steam rail cars in service. J. Instn Loco. Engrs, 1929, 19, 143-63. Disc.: 163-70; 314-33. 2 illustration, 6 diagrams, 12 tables. (Paper No.240).
Includes economic as well as technical aspects.
Kelway-Bamber, H. Modern steam rail coaches. J. Instn Loco. Engrs, 1924, 14, 537-48. Disc.: 548-54. (Paper No. 170).
General comment on the Sentinel type, plus a detailed analysis of operation in Jersey.
Matthewson-Dick, T. Address by the President. How they run. J. Instn Loco. Engrs, 1967, 57, 155-96.
He had experience of both the more common types and of the articulated Phenomena used on the South Blyth to Monkseaton service where it connected with the electric services. It was capable of 45-60 mile/h and had a power to weight ratio of 4¼. Two illustrations of the Woolnough boiler are included. He did not recall much engine trouble, but there was constat anxiety over the boiler feeds.
Poultney, E.C. Poppet valves as applied to locomotives. J. Instn Loco. Engrs, 1930, 20, 704-6. Disc.: 706-15. (Abstract of a lecture).
The lecture was associated with a visit to inspect D49 locomotives (with Lentz OC and RC valve gear) and a Sentinel shunter at Neville Hill Depot, Leeds.
Tritton, J.S. Rail cars. J. Instn Loco. Engrs, 1934, 24, 365-401. Disc. : 401-19. (Paper No. 322).
The paper is concerned with internal combustion units, but comparisons with Sentinel automatically-fired units are given.
Willans, K.W. The geared steam locomotive. J. Rec. Trans. jr lnstn Engrs, 1928/29, 39, 23-63. Disc.: 263-6. 10 illustration, 13 diagrams, 2 tables.
Clayton, Sentinel and other units are described.
Willans, K.W. Water-tube boilers suitable for locomotives. J. Instn Loco. Engrs, 1930,
20, 157-79. Disc.: 179-96; 411-18; 688-92 + 6 folding plates. 2 illustration, 22 diagrams (Paper No. 255).

Based mainly on Kerr Stuart experimental work on a Perkins boiler, but most of the other small water-tube boilers are mentioned, especially in the discussions.

Other material
Some of the older material, especially that by Kidner, is probably now of dubious value

Bowtell, H.D.and Cook. A.F. The steam railcars of the L.N.E.R.. Railways, 1950, 11,179-80. 3 illustration
A stock list.
Bradley, D[onald] L[aurence] Locomotives of the Southern Railway. London, 1975. Volume 1.
Pp 71-2 briefly survey the Southern railbus No. 6 ans the Drewry railcar No. 5.
The LNER railcars in Scotland. C.S. Carter and A.R. Maclean. Br Rly J., 1987, 2, 275-9.
Includes note that there was a suggestion within the Scottish Area that railcars should be painted deep blue all over. Lines operated included Stirling to Balloch; Aberfoyle and Blanefield; Kinross Junction to Alloa and Ladybank; Stirling to Alloa, Alva and Dollar [KPJ Menstrie in 1946]; Thornton Junction and Methil; Hamilton to Blairhill and Shettleston; Edinburgh District to several destinations, including Dalmeny and Ratho; North Berwick, Dunbar, Penicuik and North Leith as well as Galashiels to Selkirk; Carlisle District to Port Carlisle and to Silloth; and Aberdeen District from Aberdeen to Culter and Banchory and to Dyce and Ellon.. See letter from K. Hoole in Number 17 page 351 which indicated several errors. illustration: No. 33 Highland Chieftain at Ellon; No. 313 Banks of Don at Thornton Junction in June 1934; No. 31 Flower of Yarrow on St Margaret's shed; No. 39 Protector at Langholm. Mileages achieved are quoted..
Coleford, I.C. Sentinel railcars. Br. Rlys ill., 1994, 3, 529-39; 624-34.
History of the development of the Sentinel railcars, mainly on the LNER. Development included the fitting of deflector plates alongside the chimney to stop smoke entering through the windows of the car. Includes observations on names for cars, notably those of stagecoaches. Like many articles in this journal there are quotations from official documents which give an aura of "authenticity". The second part contains several illustrations of (1) the CLC vehicles in two of which the chocolate and buff livery is clearly visible (albeit not in colour); and (2) the cars painted brown during WW2
Earnshaw, Alan. Lines to the [Carlisle] Citadel. Backtrack, 1997, 11, 531.
page 531  Sentinel Rail Car Nettle on 16 Sept 1931 (caption notes that tail loads of three vans or two coaches sometimes hauled on the lines to Langholm and Silloth).
Edgington, T.J. Railcars on the LMS. Backtrack, 2001, 15, 696-8.
Lists some of the routes on which Sentinel railcars worked, including Strathpeffer branch; the Ayr to Girvan line via Turnberry,; Wanlockhead and Horwich branches. illustration:LMS Sentinel railcar No 2233 at Perth in 1932, Sentinel railcar No 4144 ex-works (Erratum (date) on page 114 Vol. 16), Sentinel railcar No 4151 at Hamilton Central, Sentinel railcar No 4349 at Hamilton shed in 1933, List of Allocation of Sentinel railcars and workings in 1932. Most withdrawn in 1935.
EXTINCT locomotive classes the London and North Eastern "Y3" class Sentinel 0-4-0's. J. Stephenson Loco. Soc., 1958, 34, 113-14.
Hardy, R.H.N. Railways in the blood. Ian Allan, 1985.
Page 15: firing a Sentinel on the 1 in 38 gradient out of Batley 'Oil with stops at Upper Batley and Howden Clough on climb to Drighlington: "if we started to slip all hell was instantaneously let loose"
Hoole, K.  Railcars in the North-east. Rly Wld, 1957, 18, 257-61. 12 illustration
An account of the Sentinel types and of the Armstrong Whitworth diesel electric cars.
Hoole, K.  Sentinel locomotives. Rly Wld, 1958, 19, 235-40. 9 illustration, 3 tables.
Restricted to the products used on the British main-line railways.
Hoole, K.  The Sentinel railcars and locomotives of the L.N.E.R.. Rly Obsr, 1952, 22, 150-3; 175-8; 209-10; 240-2; 319-20 + 5 plates. 16 illustration, 8 tables.
Errata :1953, 23, 54; 147.
Hughes, W.J. and Thomas, Joseph L. 'The Sentinel': a history of Alley & MacLellan and The Sentinel Waggon Works. Volume 1. 1875-1930. 1973. .
This is a vital source of information about (1) the Company and (2) the development of the road steam lorries which were to greatly influence the development of the railway locomotives and steam railcars described herein. There is a section where the authors infer that Kyrle Willans may have been influential in directing Sentinel towards locomotive development citing a reference to an article by L.T.C. Rolt in Old Motor (but this aspect is covered in Rolt's Landscape with machines.
Jenkinson, David and Lane, Barry C. British railcars, 1900 to 1950. 1996.
Chapter 4: A second chance for steam: pp. 46-57. Mentions but does not illustrate Jersey vehicles and excludes Irish vehicles.
Kidner, R.W. Multiple unit trains, railmotors and tramways, 1829-1947 in : Kidner, R.W.
A short history of mechanical traction and travel. v. II: Rail. Chislehurst (Kent), Oakwood Press, 1947. [vi] 150 p. + front. + 39 plates. 354 illustration (including 260 thumb-nail skitches). Bibliogs.
The main reference consists of four separate works, most of which (but not this part) were also published separately. This part (pp. 107-50) has its own bibliography.
Kidner, R.W. The railcar, 1847-1937. Sidcup (Kent), Oakwood Press, 1939. 65 p. + 6 plates. 116 illustration (including 99 thumb-nail sketches), 7 tables.
includes a chapter on Sentinel and other steam geared railcars.
Klapper, C.F. Derwent Valley Light Railway. Loco. Rly Carr. Wagon Rev., 1929, 35, 50-3. 5 illustration
Includes details of economies which resulted from the use of a Sentinel locomotive.
Lathey, G. The hunting of the 'Steam Pig'. Backtrack, 1996, 10, 78-80.
Workings of Sentinel railcar 51914 Royal Forrester in the Leeds area during 1936/1937. Letter (page 278) claims same car worked Hertford to Hitchin. Brian Orrell (page 222) had not heard expression Steam Pig used for Sentinel railcars in Wigan/St Helens area where they were known as the Chip Train. and back;
L.M.S.R. Sentinel railcar withdrawn. Rly Gaz., 1940, 72, 394.
No. 29913 : final survivor (100 h.p.—cardan drive type).
Maggs, Colin. The branch lines of Gloucestershire. Amberley Publishing.  information gleaned from review  by RH (Roger Hennessey?) in Backtrack, 2012, 26, 443.
"the author finds room for many intriguing asides, such as the Sentinel railcar that the GWR tried out on the Tetbury branch"
Oates, G. The Axholme Joint Railway. 1961. (Locomotion papers, No. 16).
The Axholme Joint line nominally possessed one Sentinel railcar.
Railway Correspondence & Travel Society. The locomotives of the Great Western Railway. Part 6. Four-coupled tank engines. 1959.
No. 12 had an extremely short life whilst No. 13 lasted until 1946. Both entered service in 1926, but the former was withdrawn almost immediately. No. 13 is illustrated.
Railway Correspondence & Travel Society. Locomotives of the LNER. Part 9B. Tank engines—classes Q1 to Z5. 1977.
LNER classes Y1, Y3 (covered together) and Y10. Lowe indicated that the Sentinel locomotives were fitted with counter pressure braking: this is also recorded herein. Commentators on counter pressure braking have probably failed to note this exploitation of the system (it appears to have been standard practice on both the locotives and on the road vehicles).
Railway Correspondence & Travel Society. Locomotives of the LNER. Part 10A. Departmental stock, locomotive sheds, boiler and tender numbering. 1990?..
Some Y1 and Y3 types as painted in Departmental Stock series are illustrated. The self-propelling ash cranes are difficult to find, but are considered on page 19 under Scottish Area. There were two of these Sentinel Works Number 8157 (LNER 773044) and WN 8565 (773066). They were not regarded as locomotives yet were required to travel on running lines and were passed to run at 24 mile/h. The former worked at Eastfield and Parkhead in Glasgow where it was known as Stoorie Annie. The latter worked between Haymarket and St Margarets (but there were problems with track circuits), and later at Dundee and Thornton. Figures 53-5.
Railway Correspondence & Travel Society. Locomotives of the LNER. Part  10B. Railcars and electric stock. 1990. 150pp.
Includes Sentinel and Clayton steam railcars which were numbered with the carriage stock: this latter causes difficulties for the researcher as less information wass available on carriage transfers.
Read, R.E.G. Good-bye to the steam railcar. Trains ill., 1949, 2, 50-2. 5 illustration
Rolt, L.T.C. Landscape with machines. 1971.
Now available within The landscape trilogy. 2001. This shows Rolt's involvement with a Sentinel agricultural tractor, and with his observation of Kyrle Willans' reconstruction of a Manning Wardle at Blackwells engineering works in Northampton in 1922. An industrial locomotive became in effect the first Sentinel locomotive by using the chassis of Ancoats (owned by the Isham Ironstone Co) combined with boiler , engine and chain drive from a Sentinel lorry. The Ironstone Company was very impressed by the locomotive's performance. On page 92 Rolt noted that Kyrle Willans' work for Sentinel had made him very conscious of the shortcomings of the Sentinel boiler. Rolt was also well aware of the limitations of the Sentinel boiler whilst using th Sentinel agricultural tractor at Pitchill. Later Rolt encountered Abner Doble at the Sentinel Works. The flash steam waggon was capable of doing the round trip from Shrewsbury to Glasgow and back in less than twenty four hours.
Rutherford, Michael. Bogie steam locomotives - Part 2. [Railway Reflections No. 42]. Backtrack, 1995, 9, 183-90.
Describes the bogie locomotive developed for Colombia and tested in Belgium where it was demonstrated to Gresley, Bulleid, Clayton, Stanier and Hawksworth.
Rutherford, Michael. Was there a future for steam? - Part 1. [Railway Reflections No. 4]. Backtrack, 1995, 9, 183-90.
This part was mainly concerned with the development of high performance steam engines for road vehicles, and the adaption of this technology to railway traction. Stephen Alley was the founder of the Sentinel operation associated with steam road and railway vehicles. and development might have gone much further had the financial state not been so severe during the 1920s and 30s, specially once Doble became involved in the firm. Doble's best known contribution was to high performance steam automobiles, but similar technology was applied to a railbus for the Southern Railway and a locomotive for the LMS. The author also mentions Kyrle Williams advanced water tube boilers, but the work ended with the failure of Kerr Stuart, and the Swiss Locomotive Company's high pressure locomotive with double acting Uniflow cylinders with jackshaft drive and the application of the Woolnough marine water tube boiler to Sentinel railcars.
Rutherford, Michael. Some reflections on the narrow gauge. Part 4. (Railway Reflections No.132). Backtrack, 2007, 21, 437-46.
Includes accounts of the performance of Sentinel-Cammell railcars in the Peruvian Andes via Brian Fawcett's Railways of the Andes and of the use of oil-fired locomotives on the Egyptian Delta Light Railways and on the 2ft 6in Barsi Light Railway in India which:incorporated Everard Calthrop's ideas for very light axle loads. Includes diagram of the metre gauge bogie locomotives supplied to Colombia in 1934.
Sewell, G.W.M. Letter. NBRSG Journal, 1987, (31), 29
Railcars in Scxotland, mainly on LNER lines, but also some mention of LMS services; also as experienced by a passenger
White, Malcolm. The Yarmouth train. 2005. page 70 upper
LNER Railcar Tantivy photographed at one of the camp halts.on the M&GNJR between Stalham and Yarmouth Beach during the summer of 1933: it carried 22,276 passengers between 17 July and 19 September
[WITHDRAWAL of LMSR. Sentinel railcar No. 29913]. Loco. Rly Carr. Wagon Rev., 1940, 46, 83.

Bogie locomotive (metre gauge)

Tritton, Julian S. Locomotive limitations. J, Instn Loco. Engrs, 1946, 36, 283-323. (First Sir Seymour Biscoe Tritton Lecture)
Figure 7 shows the now well-known photograph of bogie locomotive for Colombia in Belgium with distiguished guests, including Gresley and Bulleid. Noted that locomotive had excellent ride and reached 56 mile/h.

Road vehicles

The Super-Sentinel Waggon (lorry) was introduced in April 1923 at about the same time that the company started to manufacture locomotives and railcars. In many respects these vehicles were at least comparable with contemporary internal-combustion-engined trucks.

Patents (Hughes & Thomas:  most information requires verification) Note many US, Canadian and French patents unearthed, but not listed

Alley & Simpson 1380/1904

GB patent 8566/1904 Stephen Evans Alley Improvements in and relating to vertical steam boilers. Applied 14 April 1904. Published 23 February 1905
Vertical boiler with superheater used in lorries and locomotives until 1951: capable of being used on 1 in 6 gradients. Confirmed Espacenet
GB patent 13452/1907Improvements in steam boilers. Stephen Evans Alley and George Woodvine. Applied  11 June 1907 Published 30 April 1908
Confirmed Espacenet

Engine (low speed)
Alley & Simpson 4248/1905
poppet valves

George Woodvine 124,634/1918

Differential/crankshaft (these all appear to be Applications for Patents)
Alley 15,912/1916
Alley & Thomson 24,984/1919
Alley & Woodvine ??/
Alley 1132/12 January 1923


5719/1917 George Woodvine
18/1921 Alley

Oil burning
6024/1924 Alley & A.C. Hutt
15,337/1924 Alley & Hutt

Revrsing mechanism

Agricultural tractors

Alley 9166 1923

Locomotive types (patents)

Alley and L.E. Slade 222,955 11 July 1923
Works number 5156 July 1923 for 750 mm gauge.

Central engine type (CE)
Alley 239,932 18 June 1924
Unlike the road vehicles the locomotives lacked a differential and the velocity in reverse was identical to that in forward.

Double engine (DE)
248,835 December 1924
Each engine drove a separate axle, and the patent allowed for multiple boilers and for articulation, but usually a 200 hp boiler supplying 4600 lb steam/hour was employed. It was to large for top firing and had a firedoor just above footplate level. A squared firebox was used and was not supplied by Galloways as this firm had gone out of business.

From March 1925, and possibly before, the locomotive version of the engine was redesigned for greater efficiency and economy in the valves, but the modifications could not be applied to road vehicles because of lack of space.

Double-geared locomotives (DG)

Alley 289,505 1927

The Company

Unlike most other locomotive manufacturers this company did not set out to manufacture locomotives or steam railcars, but had its origins as 'The shipyard on dry land' (J.G.R. Woodvine Introduction to Hughes). This shipyard began in Bridgeton in Glasgow and moved to Polmadie (better known to railway enthusiasts as the location of a major motive power depot. The major instigator of this concern was Stephen Alley, but it was his son, Stephen Evans Alley, who brought the firm capable of manufacturing locomotives and railcars into being.

The Sentinel Engineering Works had been founded by Alley senior in association with John Alexander MacLellan in 1875 in Bridgeton, Glasgow, and the firm moved across the Clyde to Polmadie in 1880. The firm built prefabricated ships and engines for paddle steamers and marine auxiliary machinery. In 1905 the firm bought its way into steam by buying the rights of Simpson & Bibby and moving the key people to Glasgow where the Sentienl Steam Waggon was developed.

In 1915 this activity was moved to a new factory at Shrewsbury alongside the LNWR mainline to Crewe. The development included model housing for the workforce where the factory provided hot water for domestic use including central heating. Unfortunately, the piping corrided by the late 1920s and gas-fired heating had to be substituted for the central source.

The boiler shells and fireboxes were supplied by Galloways of Manchester and Abbotts of Newark. On 17 May 1918 the "Sentinal Waggon Works" came into being with a Registered Office in Shrewsbury and independent from Alley & MacLellan Ltd in Glasgow. Stephen Evans Alley was Chairman of the new company

In 1925 a separate company, Sentinel Industrial Locomotives Ltd was established with its Office in Chester and with Arthur Thomson as its Assistant General Manager, but this activity had to be merged with that of the Railway Department back at Shrewsbury in 1928.

Doble boilers/advanced compound engines

Abner Doble, the American steam car designer, joined Sentinel briefly and this led to the locomotive constructed for the LMS which was fired with liquid fuel and was intended to be comparable with the internal combustion locomotives being evaluated at the same time. It also led to the Southern railbus and to the metre gauge locomotive for Colombia (which was inspected in Belgium by a party which included Gresley, Bulleid and Hawksworth). See especially Trans. Newcomen Soc., .

Sentinel geared steam locos., Egyptian State Railways. Locomotive Mag., 1938, 44, 103-5.. 2 illustrations, 3 diagrams (including 2 side elevations)
Four locomotives built by North British Locomotive Co. with Sentinel engines. Each totally enclosed engine had two 11 x 12in cylinders driving wheels of 3ft 8¾in diameter. The driving wheels were not coupled: thus in Whyte notation they were 2-2-2-2. They eliminated hammer blow. They had 200 psi Belpaire boilers which were identical to those used in 4-4-0 locomotives supplied in 1937 (see LM, 43, 304). The valve gear was modified Hackworth. An industrial 2-2-2 saddle tank with two Sentinel engines is also described.


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