After 1930 the only locomotives newly introduced on the line were standard types of the L.M.S., S.R. and G.W.R, etc.
These included:

LMS 'Black Fives'
8F 2-8-0's
Ivatt Class 2, 2-6-0's
Ivatt Class 2, 2-6-2T's
Bullied 'West Country Pacifics' (from 1951)
Collett 0-6-0's & ex GWR Pannier Tanks were used mainly on the northern section of the line & the branch, although they managed to appear nearly everywhere over the years.

From 1954, BR Standard type locos were used on the line, including:

Class 3, 2-6-2's
Class 4, 4-6-0's
Class 5, 4-6-0's
In 1960 the Class 9F 2-10-0's were introduced.
1964 saw the last new type of loco to appear on the S&D, these was the BR Class 4, 2-6-4T loco's.

Motive Power 1930 - 1966

At the beginning of 1930, there were 80 locomotives, of six different wheel arrangements in use on the S&D:

• 14 - 4-4-Os of four types, the most recent of these were the L.M.S. class '2P' Nos. 633-635, used for passenger work over the main line.
  
• 11 - 2-8-Os, six small and five large-boilered, engaged on heavy freight work north of Templecombe.
  
• 26 - 0-6-Os of three types, the most modern being Nos. 4557-4561 of L.M.S. standard class '4F', used on heavy passenger trains at times of pressure.
  
• 12 - 0-4-4 tanks for branch and local passenger work.
  
• 15 - 0-6-0 tanks, in two types, for shunting and banking work Nos. 7150-7156, (later 7310-7316), were L.M.S. standard class "3F" examples.
  
• 2 - 0-4-0 Sentinel tank engines, Nos. 7190 & 7191 used for shunting duties at Radstock.

No immediate radical change was made apart from re-numbering, change of livery and lettering, it being the policy to allow the older non-standard machines to be withdrawn and replacements to come in the shape of L.M.S. standard or ex-Midland types already common to the line.
However, one or two of the replacements in the 1932-33 period were quite unusual, such as ex-Midland 2-4-0 No. 155, a pair of Kirtley 0-6-Os, and an ex-Lancashire & Yorkshire 0-6-0 No. 12140, this later found itself on the Wells branch.
A couple of years later in 1935, No. 2103, a 4-4-2 tank of L.T.S.R. origin had a stay of a few months duration on the line.

In 1932 the last survivor of the 1896/7 M.R. Derby built 5 ft. 9 in. 4-4-0s, No. 303 (originally No.45), was withdrawn, as was No. 1207, the last of the 1200-1207 0-4-4 tanks, and No. 2884, the last of the 11 0-6-Os of the 2880-2890 series. The same year two of the large-boiler 2-8-0s, Nos. 13809 and 13810, received smaller boilers while undergoing repairs at Derby works.
A couple of years later the last of the 0-6-0 tanks of the 1500-1507 batch, No. 1506, made its final journey and, early in 1938, No. 321, the survivor of a pair of similar 4-4-0s, was scrapped.

It was apparent by 1938 that, with the completion of a bridge strengthening programme on the ex-Midland line between Bath and Mangotsfield, rather more modern power could be introduced, and after a trial run by No. 5228 in March, six of the Stanier class '5P5F' 4-6-Os were transferred to Bath and, on May 2nd they entered regular traffic, the southbound 'Pines Express' being hauled that day by No. 5440.
Over the difficult section of the Mendips the 4-6-Os were eventually allowed to haul without assistance 270 tons, compared with allowances of 210, 240 and 315 tons for class '2' 4-4-0s, class '4' 0-6-Os and ex S.D.J.R. 2-8-Os respectively.
With the advent of the 4-6-0s, three taper-boiler Stanier 2-6-2 tanks, Nos. 179-181 were sent to Templecombe and Bath for banking and local passenger duties.

With the onset of hostilities in 1939 the re-equipping of the S.D.J.R. locomotive stock with standard designs was cut short. All but two of the class '5' 4-6-Os were sent away almost immediately and eventually there was a period when none of the class remained on the line. Replacements came in the shape of No. 1046, a compound 4-4-0, and, in 1941, 17 ex-London & South Western Railway locomotives, on loan from the Southern and consisting of the whole of the 'S11' class 4-4-Os Nos. 395-404, one 'T9' class 4-4-0 No. 304, and Nos. 1-6 of the 'T1' 0-4-4 tank class. Most, if not all, of the loaned 4-4-Os were fitted with tablet-exchange apparatus and performed on the main line, although several of the 'S11' class migrated to other Midland sheds, while the tank engines were engaged on branch duties.

In 1943, three L.M.S. standard class '8F' 2-8-Os appeared on the line but their stay was only for a month or so.
In the same year 'Crab' parallel-boiler 2-6-Os became common performers on the main passenger trains of the day.
In the summer of 1944, No. 5440 returned to Bath shed and was later joined by the newly-constructed No. 4844. This signalled a gradual return to the position before the war and, by early 1945, the Southern locomotives had left for their own metals and, once more, Midland 0-6-Os and 0-4-4 tanks were part of the Somerset & Dorset scene.

Shortly after the end of the War in 1945, the nationalisation of the railways was announced, although before this a stranger from ex-Lancashire & Yorkshire stock, an 0-4-0 tank, No. 11202, was transferred to Radstock for colliery work and another S.D.J.R. class disappeared when No. 1230, the last of the 1230-1232 0-4-4 tanks, was withdrawn in 1946.

Shortly after nationalisation little immediate change was made, for although the Southern Region was allocated the whole of the line and branches, the motive power arrangements remained mainly unaltered.
In November 1948, No. S21CI49 powered a football excursion from Bournemouth and established the claim of being the first Pacific-type locomotive to traverse the route.  Over two years were to elapse before this became a regular feature. Early in 1949 2-6-0 No. 43012 was transferred to Bath shed, after having put in some appearances the previous year, and was joined by two other examples, also of double-chimney variety for the forthcoming summer traffic.

Another type new to the line was the ex L.M.S. class '2' 2-6-2 tank which made its debut in the autumn of 1949, when Nos. 41240-41243 appeared on Highbridge local services as well as working to Bristol from Bath.
In February 1950 the Southern Region took over Bath and the other S&D sheds from the London Midland Region and absorbed them into its own '71' group. Some 69 engines were affected, as shown in the table at the bottom of this page.
In April 1950, the Western Region took over the section of line from Cole northwards, although this did not alter the motive power arrangements.

About a year later the Southern authorities examined the question of the haulage of the heavier trains in an effort to dispense with piloting over the steeply graded Mendip sections. Six Southern light 4-6-2s were transferred to Bath after trials by No. 34109 during March. Three of these were soon back at Bournemouth when it was found that the greater power available, compared with the class '5' 4-6-0s, was not quite as advantageous as had been originally hoped. If the advent of the Stanier 4-6-Os had not resulted in quite as striking an advance over previous standards as had been expected, how much less was the case when the Southern 4-6-2s, with their low adhesion arrived, as the Mendip Hills permitted no rousing rushes, only solid slogging in the vicinity of Masbury or out of Bath. Undoubtedly the 4-4-Os had thrived on hard pounding and could be (and were), thrashed, and it was that class, together with the 2-10-Os yet to come, which could be nominated as the classic passenger performers of the line.

4MT No.75072 at Templecombe

In late 1952 No. 51202 returned to the London Midland Region, as did the ex L.M.S. 2-6-Os in mid 1953. Over optimistic trials with 'U' and 'UI' class 2-6-Os Nos. 31621 and 31906 respectively in March 1954 brought no changes, although in May a new class, the B.R. standard '5' arrived in the shape of Nos. 73050-73052, straight from construction, displacing three of the L.M.S.-type class '5' 4-6-0s.
Two more B.R. standard classes made their appearance in 1955, the class '4' 4-6-Os and 2-6-Os, the former being Nos. 75070-75072 allocated to Bath to take over piloting and local duties performed by the 4-4-0s, and the latter by way of a daily Eastleigh duty to Bath.
That year, miles away at Holbeck, No. 40323, the last of the S.D.J.R. 322-326 series, was withdrawn.

Eventually, in February 1958, the provision of motive power for the Somerset & Dorset came under the control of the Western Region. No immediate alteration took place other than the return of the last two of the L.M.S. class '5' 4-6-0s, one of which was the faithful No. 45440, to the L.M.R. These were two of the 66 locomotives handed over to the Western Region at the end of the Southern's reign. One or two B.R. class '3' 2-6-2 tanks were introduced and, as the Southern still had three duties worked from Bournemouth on summer Saturdays, modified 'West Country' 4-6-2s appeared, the first being No. 34039 in 1959.

Apart from a War Department 2-10-0 and a '56xx' class 0-6-2 tank making odd appearances, nothing of great mention occurred until 1960 and then only ironically, when the fate of the Joint line could be predicted did motive power to match summer Saturday demands materialise. Standard B.R. class '9F' 2-10-0 No. 92204 made a trial run in March and in company with Nos. 92203, 92205 and 92206 took up duties in Bath for the summer traffic. These engines were allowed to take 400 tons unassisted over the Bath to Evercreech Junction section and pilots could be dispensed with at last, although in the event they were still often provided.
Locomotives of this type re-appeared in 1961 and also for the final year of through traffic from the North to Bournemouth.

Meantime replacement of the stock inherited by the Western Region had been accelerated. The need for the Sentinels at Radstock had gone and so No. 47191 was withdrawn in August 1959, and its companion, No. 47190, in the February the following year.
G.W.R. Collett-type 0-6-Os were introduced, No. 3218 replacing No. 43218 in the spring of 1960, and by August 1962 the last of the S.D.J.R. engines of the smaller 0-6-0 arrangement, No. 43216, was retired. The sole 0-4-4 tank, No. 58086, had finally gone in August 1960, after a long period out of commission and, with the re-introduction of the ex L.M.S. 2-8-Os after a 20-year break, in the autumn of 1961 the writing was on the wall for the S.D.J.R. 2-8-0s. No. 53804, the last representative of the first batch, remained until February 1962, while members of the second batch lingered on until No. 53807 was finally withdrawn in September 1964.
The class '2' 4-4-Os piloted for their last summer in 1961 and by the end of the following summer, No. 40634, the last survivor of the S.D.J.R. trio built in 1928, was withdrawn from Templecombe, in 1962.

The 'customary policy' of providing little service or modern equipment to doomed lines was in operation by 1963 and a large turnover of stock commenced due to locomotives constantly being withdrawn and scrapped rather than being repaired.
Somewhat oddly, two class '9' 2-10-Os re-appeared in that summer for the by now non-existent through trains, only to vanish again quickly!
Another new class was introduced in late 1964 in the form of the ubiquitous B.R. class '4' 2-6-4 tank. No difficulty with the lightly loaded local workings were encountered by these engines.

At the end of 1964 locomotive stock had fallen to just 34 engines. The S.D.J.R. 0-6-0 was withdrawn at the end of 1964 and was the last of its class on the line. By mid-summer 1965, the Collett 0-6-Os had gone and so, for the first time for many years, no 0-6-0 tender engine remained on the Somerset & Dorset.
The last 0-6-0 built by Armstrong-Whitworth, No. 44560, was withdrawn from Gloucester shed in August 1965, the final months of its career having been of a nomadic character with reported appearances at Banbury and Southall, thus leaving two 0-6-0 tanks, Nos. 47313 & 47314 transferred to the London Midland Region as the last examples of S.D.J.R. locomotives still running.

News of the passenger closure came in the autumn of 1965 and 1966 saw the end of a fascinating cross-country route.

To the varied types of steam engine (diesel traction in any form was virtually unknown) which have regularly done battle with the Mendips there must be added the Southern 'Schools' 4-4-0s, the L.S.W.R. '700' 0-6-0s, Caprotti valve-gear class '5' 4-6-0s, L.N.E.R. 'B12' 4-6-0s, S.R. 'Q' 0-6-Os and others, making infrequent or once-only visits on special trains, to contribute to as fine and brilliant a kaleidoscope of locomotion as any joint line could possibly expect.