Between 1864 and 1905 fifteen distinct classes and sub classes of 0-6-0 tank engines were built at Swindon and Wolverhampton, providing the Great Western with over 1,100 light goods, shunting and branch passenger engines. The 5700 and later 8750 class pannier tanks can trace their origins back to these saddle tanks from the Armstrong and Dean era.

856 of the 1901 class introduced 1874
  (G W Trust / P J T Reed collection)
A good proportion of these earlier saddle tanks were converted to pannier tanks to prevent problems with injectors due to overheating of the water in the saddle tank. The 57XX, although separated from them by 24 years, were an almost unaltered continuation of the saddle to pannier tank conversions of the 27XX with a reversion to the spring arrangement and non-fluted coupling rods of the previous

"1854" class of 1890. These in turn sprang from the "1813" class of 1882 and the very similar Wolverhampton "645" class of 1872. Remarkable not only for the length of their ancestry but also, once replacement building started, for their numbers, which reached a total of 863 engines in twenty years, they thus became the most prolific class on the G.W.R.

Their dimensions were:-

8750 Pannier Tank Weight Diagram

Cylinders. Diam. 171/2", Stroke 24".
Boiler Barrel 10' 3"
Diam. outs. 4' 5" and 4' 37/8".
Pitch 6' 113/4"
FireboxLength outs. 5' 4"
Tubes No. 2,     diam. 51/8"
No. 233, diam. 15/8"
Heating surface Tubes; 1075.7 sq. ft.
Firebox 102.3 sq. ft.
Total 1178.0 sq. ft.
Grate area15.3 sq. ft.
Boiler pressure200 lb.
Wheels4' 71/2"
Wheelbase7' 3" + 8' 3" total 15' 6"
Weight (full) Leading 16t 15c
Driving  16t 15c
Trailing  14t   0c
Total     47t 10c
Tractive effort
22,515 lb
Tank capacity1200 gallons
Coal capacity3t 6cwt
Height at top
of chimney
12' 31/16"

5700 Class

By 1929 superheating, had been found of little value on shunting engines, the two 51/8" superheater flues, being incerted in the top corners of the firebox tubeplate to prevent cracking at these points. The 200lb boiler pressure was higher than on the older engines and enclosed cabs with enlarged bunkers were fitted from the start.
5700 Official Swindon photo G W Trust / P J T Reed collection

Externally the chief feature to distinguish them from the older engines was the universal cast iron chimney. Of the first one hundred engines, fifty were built by the North British Locomotive Co. Ltd., Nos. 5700-24 at the Hyde Park Works and Nos. 5725-49 at Queens Park. Of the Swindon engines Nos. 5780-99, then Nos. 5768 & 70-8 had boilers on which the steam supply to the fountain in the cab was taken from the dome in a covered pipe along the tank top. This feature was discontinued, but the boilers found their way to other engines before it was finally removed.
Nos. 5790-99 were built with Automatic Train Control apparatus and the earlier engines were also equipped in the next few years. Two hundred further engines were built in 1929-31, all by outside firms under a Government scheme to alleviate the effects of the trade depression. These were -Nos. 6700-49, 7700-99 and 8700-49, of which Nos. 6700-49 had steam brakes only and three-link couplings, but as there was little work for this batch most of them were stored for a couple of years. The A.T.C. apparatus was put on Nos. 7750-99, 8700-49 on arrival at Swindon and on Nos. 7700-49 a few years after they were built. Nos. 5700-99, 7700-99 and 8700-49 were fitted up for vacuum brake but Nos. 5700-49 were built without steam heating apparatus although several subsequently acquired it. Nos. 7700-25 / 75-99, 8700-49 arrived with polished brass safety valve covers, most of which were soon painted over, although in later years many of the class had again been brightened by the removal of the paint.

Condensing Engines

9700 (converted from 8700)
G W Trust / P J T Reed collection
For many years engines with condensing apparatus (0-6-OT's of the " 633 " class and 2-4-OT's) had worked over the Metropolitan lines to Smithfield. These older engines were now becoming due for replacement and No 8700 was converted to a condensing engine in March, 1932. The tanks were cut back at the smokebox end, the capacity being reduced to 1,080 gallons, and a vertical feed pump fitted on the right side.

Branch pipes from the smokebox conveyed exhaust steam to the centers of the tanks which were provided with steam vents. The weights (full) became 17 tons 7cwt. + 17tons 7cwt. + 16tons, total 50tons 14cwt.

As a result of experience with this proto-type ten new engines, Nos. 9701-10, were built at Swindon in the following year. On these the tank capacity was increased to 1,230 gallons by forming the rear part of the tanks into side tanks and a much improved form of cab with rounded roof, much larger windows and sliding shutters adopted. Coal capacity was however reduced to 2tons 16cwt. At the same time the boilers supplied had slight modifications (Class PJ). No. 8700 was similarly modified and re numbered 9700 in January, 1934. Nos. 9700-10 had special A.T.C. apparatus which was automatically clipped up clear of the live rail upon entering an electerfied section and released on leaving it. The weight (full) was increased to 503/4tons (16tons 16cwt. + 17tons 4cwt..+ 16tons 15cwt).

8750 Class

Subsequent engines starting with No. 8750 were all built with improved cabs, class PJ boilers and A.T.C., with the exception of the second No. 8700 which inherited the cab and number plates of its predecessor. The class was now sub-divided into 5700, 8750 and 9700 condensers groups. To prevent steam from the whistles obscuring cab windows small deflector plates were fitted to guide the steam flow over the cab roofs. 8750 G W Trust / P J T Reed collection

No. 9773 was the first engine to be modified and two years later commencing at No. 3774 or thereabouts, a larger type was introduced. This was standard for the engines with large cabs, the shorter pattern being fitted to the earlier engines. Further improvements were incorporated in No 9795 (9/36) and subsequent engines with pocket steps welded onto the bunker on the firemans (L.H.) side and additional handrails to facilitate access to the bunker. Engines built prior to these modifications were gradually brought into line as they passed through the shops. The weight was increased to 49tons, 17tons - 17tons - 15tons.
In 1942 a new type of top feed appeared, with separate clackboxes housed in a much taller cover than the Churchward pattern, and internal delivery pipes in place of trays. The point of delivery was very carefully chosen to prevent trouble from local cooling. No. 8770 and 5735 were the first of the older engines to be modified, and No. 4656 (5/43) the first to be built as new, although it did not seem to have become standard for new construction until 1944. From then top feed apparatus had been put on many of the older boilers and some engines built with it, had lost it due to boiler interchange. Nos. 6750-79, like Nos. 6700-49, had steam brake fittings only.
During the Second World War the " 5700 " class began to be used at Didcot Ordinance Depot and spark arresting chimneys were fitted to Nos. 3709/21, 4601, 5710/44/52, 7709, 8738/57 and 9722 while No. 7709 also had the 'bird-cage' type. Nos. 5757 and 7713 had however acquired spark arresting chimneys by 1938 and 1937 respectively.
In -May, 1946, No. 7722 was fitted with winding gear for working the Pwllyrhebog incline on the Taff Vale line, also one or two engines had the upper lamp iron moved to the smokebox door.

Allocation and Work

So far as axle loadings would permit, the class was distributed throughout the system and only a few sheds did not have them. In 1950 it was decided to allow the class (except -Nos. 9700-10) to run over "Yellow" routes due to their negligible hammer-blow so that by February 1954, only Truro, Abercynon, Treherbert, Aberystwyth and Machynlleth had no allocation.

The distribution by Districts in February 1954, was London, 121; Bristol, 112; Newton Abbot, 61; Wolverhampton, 125; Worcester, 33; Newport, 178; Neath, 139; Cardiff Valleys, 83; Central Wales, 6. The other five were at Birkenhead, having been classed as London Midland Region stock with effect from 19th April, 1953.

The 67XX were not as widely spread as the rest of the class. as they were purely shunting engines with steam brake only. In 1954 they were shedded as follows; Swindon, 4; Newport Pill, 20; East Dock, 1; Swansea Paxton Street, 2; Cardiff East Dock, 21; Barry, 19.

Returning to the engines fitted with vacuum brake ejectors, not only were they used for shunting and local freight working but were used quite extensively in most areas for branch and short-distance main line passenger trains. With comparatively light loads they often made some very lively running and were occasionly used as standby engines for those of larger classes, and their efforts to keep time with heavy loads were often accompanied by firework displays!

Under British Rail they were Power Class 4F and the standard livery was unlined black, although there were exceptions that were lined, and many had the safety valve covers polished. Nos 6760-79, 9673-82 were built with smokebox number plates and all but Nos. 3656 and 3742 of the earlier engines were fitted later. It would seem that all Swindon built locos had cast iron cabside numberplates but the specification for contractor built numberplates was usually brass.

No. 7711 was transfered to the London Transport Executive in October, 1956, and becoming L.T. No. L90 was repainted in lined maroon livery (the first of several).


By 1956, the closing of branch lines and the advent of diesel shunting engines had combined to make the earliest engines of the class redundant and the first to go started with 3/56; 5700/62, 10/56; 5792, 7711(L90). The mileages of those withdrawn being between 500,000 and 556,000.

Build Dates

5700-49North British Locomotive Co. Nos. 23818-672561929
6700-24W. G. Bagnall -Nos. 2381-24052621930
7700-24Kerr Stuart Nos. 4435-592631930
7725-49North British Locomotive Co. Nos. 23921-452641929-30
6725-49 Yorkshire Engine Co. Nos. 2249-73 265 1930-1
7775-99 Armstrong Whitworth Nos. 1131-55 271 1930-1
8725-49 W. G. Bagnall Nos. 2422-46 272 1930-1
8700-24 Beyer Peacock Nos. 6680-6704 273 1931
7750-74 North British Locomotive Co. Nos. 24038-62 274 1930-1
9701-10 Swindon 282 1933
8750-98 8700 Swindon 282 1933-4
Swindon 285 1934-5
9760-84 Swindon 293 1935-6
Swindon 299 1936-7
3735-84 Swindon 306 1937-8
Swindon 314 1938-9
3635-84 Swindon 325 1939-40
Swindon 330 1940-2
4635-60 Swindon 336 1942-3
Swindon 352 1943-5
9622-41 Swindon 355 1945-6
9642-51 Swindon 356 1946
Swindon 362 1946-7
9662-72 Swindon 370 1948
6760-9 Swindon 374 1948-9
9673-82 Swindon 378 1949
6770-9 Swindon 379 1950

The Locomotives of the
Great Western Railway
Part Five
Six-Coupled Tank Engines
RCTS 1958


3650Didcot Railway Centre
3738Didcot Railway Centre
4612Bodmin & Wenford Rly
GWR no. 5764, LT no. L93Severn Valley Railway
GWR no. 5775, LT no. L89Keighley & Worth Vly Rly
GWR no. 5786, LT no. L92South Devon Railway
7714Severn Valley Railway
GWR no. 7715, LT no. L99Bucks Railway Centre
GWR no. 7752, LT no. L94Birmingham Rly Museum
7754Llangollen Railway
GWR no. 7760, LT no. L90Birmingham Rly Museum
9600Birmingham Rly Museum
9629Pontypl & Blaenavon Rly
9642Dean Forest Rly
9681Dean Forest Railway
9682North Norfolk Rly

Correct as far as known at March 2001.

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