M7 0-4-4T LSWR Drummond 30021 – 60, 30104 – 12, 30123 – 33, 30241 – 56, 30318 – 24, 30328, 30356 – 7, 30374 – 9, 30479 – 81 & 30667 – 76

M7

Power Classification 2P
Introduced 1897 – 1911
Designer Drummond
Company LSWR
Weight 60t 4cwt
Driving Wheels 5ft 7ins
Boiler Pressure 175psi
Cylinders Inside – 18.5in x 26in
Tractive Effort 19,755lbf
Valve Gear Stephenson (slide valve)

This was a numerous and successful breed of tank engine, originally procured to speed up LSWR suburban services.

The M7 followed in the footsteps of an earlier 0-4-4T design laid out by Chief Draughtsmen at Nine Elms, under the direction of Adams, the company’s then Locomotive Superintendent. Adams claimed he felt safer riding a bogie engine, and a four-coupled design with large driving wheels would remain stable at relatively high speeds. His counterpart on the LB&SCR, Stroudley, was keen to forgo the 0-4-4 wheel arrangement, for he considered that when running forwards, the lateral control springs of the rear bogie had too strong an influence over the front driving wheels. Indeed, in terms of tender locomotives, bogie designs had generally been avoided because at the time (circa 1885), the largest turntables in use could only just about accommodate an 0-6-0 engine and its tender. Enlargement of many turntables was considered too costly, because it involved expensive alterations to other infrastructure. Unperturbed by Stroudley’s concerns over a bogie tank engine, Adams introduced the class 415 Radial Tank 4-4-2 in 1882, the class A12 0-4-2T in 1887, the class T1 0-4-4T in 1888, and finally, the class 02 0-4-4T in the following year. These types were primarily employed on intensive commuter services from Waterloo, prior to electrification in the following century.

 0415 0415 class Radial Tank introduced in 1882
 a12 A12 class introduced in 1887
 02 O2 class introduced in 1889
 t1 T1 class introduced in 1894

Adams retired from the LSWR in May 1895 through ill health, and in the following August Dugald Drummond became the company’s Locomotive Superintendent at Nine Elms. Drummond had previously worked in Scotland on the Caledonian, North British and Highland Railways in various capacities

In his new post, Drummond immediately set to work on a new class of tank engine, with the intensive suburban services from Waterloo in mind. They were developed from the Adams T1 and O2 classes with modified boilers and an increase in boiler pressure and cylinder size. Drummond drew upon his previous experience with the successful London Brighton and South Coast Railway D1 class 0-4-2T, whilst he was works manager at Brighton in the early 1870s, and his own 157 class of 1877, on the North British Railway in Scotland. It was the heaviest 0-4-4 type ever to run in Britain. As per those engines procured during his time with the Caledonian Railway, he opted for an 0-4-4 arrangement, although with larger driving wheels of 5-foot 7-inch diameter. In April 1896, the decision was taken by the LSWR Board to tender out the contract to build an initial batch of 25 of these engines, numbered in the series 242 to 256 and 667 to 676. The cheapest quote received was from Sharp Stewart & Co. at £2,475 per engine, significantly higher than what the company had envisaged. As a result, all locomotives were instead built in-house, the vast majority at the LSWR’s Nine Elms Works, at a cost of £1,400 each. Eventually, fourteen separate orders with a cumulative total of 105 engines as the M7 and X14 classes were put into production over a fourteen-year period. During 1909, Nine Elms Works was replaced by a completely new complex at Eastleigh, and it was at the latter where the final ten Drummond tanks were completed.

The engines were designated M7, which derived from the alphanumerical order number of the early batches at Nine Elms Works. When the first M7 tanks entered service in March 1897, the LSWR’s suburban locomotive fleet had reached saturation point. There already existed a large number of relatively new tank engines on commuter workings, procured under the leadership of Drummond’s predecessor, William Adams. Consequently, many of the first M7 engines were sent to far-flung corners or the LSWR network, as distant as Exeter and Plymouth in the west, and a little closer to the capital, at Bournemouth, Salisbury, and Portsmouth.

The fifty locomotives built from 1903 onwards featured frames 15-inches longer than earlier batches; this produced a long front overhang, under which an air reservoir was eventually fitted. In addition, engines prior to 1903 were equipped with a lever reverser, whilst later batches were fitted with a steam reverser. Post-1903 engines were also fitted with a feed-water heater. The latter was simply used to pre-heat the water before it went to the main boiler. Drummond’s past involvement in Scottish railways was reflected by the incorporation of deep-toned organ pipe whistles, as found on engines of the Caledonian Railway. This was, however, a short-lived feature which was soon replaced. A second Drummond innovation that had brief use on these engines was the spark arrestor. The first batch of 25 engines were equipped with a complicated arrestor system, which filled up the firebox with a series of hoods and deflecting plates. The spark arrestor was there to prevent burning embers and sparks from escaping through the chimney, where they could pose a fire risk. The size of the spark arrestor required a conical smokebox door to be fitted to engines, but subsequent builds without this cumbersome set-up were equipped with flatter doors.

Some sources record these locomotives as X14 class, and this designation was sometimes used to refer to the longer-framed versions, but for most purposes the two sub-classes were grouped together and known as M7. The 1904/05 construction batch moved the sandboxes back to the front splasher and new items were feed water heating, single ram pumps and balanced crank axles. For the remainder of construction from the outshopping of the 105th locomotive in 1911, duplex pumps were fitted.

Several of the most successful features of the class were used by Drummond on his other designs. Thus the boiler, cylinders and motion were identical and interchangeable with those used on his 700 class 0-6-0 freight locomotives of 1897 and the same boiler was used on his C8 4-4-0 passenger class. Only 10 of the C8 class engines were built and they appear to have had very short operating lives after being introduced in 1898.

 

 700 700 class
 M7 M7 class

When first introduced to LSWR, several of the class were allocated to work semi-fast passenger services between London and Portsmouth, Exeter and Plymouth, and Bournemouth and Weymouth. However they were withdrawn from these duties after a high speed derailment near Tavistock in 1898, following criticism by the Board of Trade inspector about the use of front-coupled locomotives on fast services. As a result the class was to become synonymous with local main line and branch workings, as well as London suburban services. They were also a familiar sight at Waterloo, where for years they worked as station pilots.

After 1912 thirty-one M7 locomotives were equipped with push-pull train capabilities with the provision of a primitive cable and pulley device. This was a modification that was designed to save time on country branch lines where the locomotive would usually have to run around its train in order to make a return journey. As a result it was possible for the driver to drive his train from a cab located at the front of a designated push-pull coach, leaving the fireman to tend the fire and operate the injectors on the locomotive footplate.

The pulley system was eventually deemed unsafe due to instances of sagging and delayed reaction. As a result it was replaced on 36 engines by a safer compressed air system between 1930 and 1937. This system had seen previous successful use on the LBSCR. Because the air compressor required extra space for installation, these conversions were confined to the long-framed members of the class.

A further four conversions to push-pull capability appeared between 1960 and 62. This was the result of short-framed M7s having long frames substituted during overhaul in order to create room for the air compressor.

In 1913, the LSWR announced electrification of its suburban lines as far out as Guildford, via Woking, Cobham, and Epsom, using the 600 Volt D.C. third rail system. In addition, Hampton Court and Shepperton branches were to be similarly treated, as were the Kingston and Hounslow Loops. The opening and electrification of the Piccadilly and District Lines respectively, combined with the spread of tramways, had seen patronage of LSWR suburban services drop significantly. Electrification was seen as the only way forward, and electric services commenced on the majority of the aforementioned routes in 1915-1916.

Naturally, this eradicated much steam from the LSWR suburban area, but the Windsor Line remained unconverted and indeed, no further electrification took place until after the Grouping. Drummond’s Tanks became increasingly used for branch line duties.

With the gradual growth of the electrification of the inner London suburban lines after 1915, the class tended to be used on stopping trains on the LSWR main line, and on services to Guildford and Reading. After the formation of the Southern railway in 1923 the class gradually began to be used, further afield, notably in the West of England, but also on branch lines in Kent, and on the former South Eastern and Chatham Railway line between Redhill and Reading.

In 1920, M7 tanks started to receive enlarged coalbunkers. When new, these engines could hold 3-tons of coal, but modification resulted in bunkers being heightened by the addition of extra metal rails, raising capacity by half a ton.

In 1921, 126 was equipped with enlarged cylinders and a superheated boiler, featuring an elongated smokebox. Reportedly, the rebuild produced an engine which consumed less coal and water than its classmates, but at the cost of raising the centre of gravity to make high-speed running unstable. In addition, oil usage was also unusually high, and the engine was deemed too heavy for many of the LSWR’s suburban lines. The results from the experiment put a stop to rebuilding a further twenty examples in the same fashion.

Following the successful use of superheating on other Drummond classes, Urie experimentally fitted a superheated boiler to 126 in December 1920, together with an extended smokebox and a Urie stovepipe chimney and larger cylinders. The additional weight of the new boiler raised the centre of gravity of the locomotive, thereby adding to problems of instability on faster main line trains, whilst simultaneously preventing its use on many branch lines. As a result, 126 was confined to the role of Waterloo station pilot, and hauled empty carriage stock between Waterloo and Clapham Junction Carriage Sidings. No further examples were fitted, and 126 was eventually broken up for spare parts in 1937.

In 1931 672 was experimentally fitted with the Strowger-Hudd automatic Warning System, but the equipment was not adopted by the Southern Region and the equipment later removed.

The LSWR was absorbed into the Southern Railway on Grouping in 1923, accompanied by the neighbouring LB&SCR and SE&CR. The M7s were the largest single class of tank engine to be inherited by the Southern Railway, and under this company’s auspices their operational scope increased. The LSWR numbering series was retained, but between 1923 and 1928 an ‘’E’’ prefix was displayed in front of the number (simply denoting Eastleigh). Several of the type were allocated to the Central Division which, in spite of the electrification mania of the 1930s, still retained large pockets of un-electrified railway. Typically, they were employed on push-pull branch services, featuring on those rural lines around Oxted and Tunbridge Wells West.

During the 1950s a substantial number of the “push-pull” fitted members of the class was transferred to the Central Section of the Southern Region, at Brighton and Horsham, replacing worn-out class D3 locomotives on the branch lines of the former London Brighton and South Coast Railway in West Sussex. A further ten were transferred to Tunbridge Wells and Three Bridges in 1955 for use on East Sussex branches. These were less well accepted by the train crews, who preferred the less powerful SECRH class. Others remained in the London area on empty stock workings, notably between Clapham Junction and Waterloo Station.

The class was gradually replaced in the southeast England during the late 1950s and early 1960s due to the introduction of further electrification, new lightweight standard steam classes, diesel shunters, and diesel-electric multiple units. By the end of 1963 the majority that remained were based at Bournemouth to work the Swanage branch.

 

Number in Service.

Built

Withdrawals No. in Service
BR Numbers Quantity
1897 30242-56

15

30667-76

10

  25

1898 30031-40

10

  35

1899 30022-26

  5

30041-44

  4

30241

  1

  45

1900 30112

  1

30318-24

  7

30356-7

  2

  55

1903 30123-24

  2

30130

  1

30132-3

  2

30374-8

  5

  65

1904 30021

  1

30027-30

  4

30108-11

  4

30379

  1

  75

1905 30045-55

11

30104-7

  4

  90

1906 30056-60

  5

  95

1911 30125-29

  5

30131

 1

30328

 1

30479-81

3

105

1912-36

105

1937 30126

    1

104

1938-47

104

1948 30672

    1

103

1949-56

103

1957

    4

  99

1958

    8

  91

1959

  16

  75

1960

    6

  69

1961

  20

  49

1962

  14

  35

1963

  21

  14

1964

  14

    0

Notes

  • All of the locomotives built up to and including 1906 were completed at Nine Elms with the ones produced in 1911 being made at Eastleigh.
  • 30126 was withdrawn in 1937 after being experimentally fitted with a 700 class boiler in 1921. 30672 was withdrawn in 1948 following falling down the lift shaft at Waterloo.
  • In 1960 30128 and 30031 swapped numbers. 30106 was withdrawn in 1960 and was reinstated in 1961 as 30667, the original 30667 having been withdrawn.
  • The last 9 locomotives of the class in service were withdrawn in May 1964.
  • 30254 was one of the first batch built in August 1897 and was one of the last to be withdrawn in May 1964. Two other engines built in 1997 remained in service until July 1963 (30249 completed in May 1897 and 30251 completed a month later). Both were withdrawn from Easleigh depot.
  • The withdrawals in 1963 and 1964 are shown by depot below.

 

1963

1964

Bournemouth

8

  10

Salisbury

1

    4

Barnstable

1

Eastleigh

4

Feltham

1

Guildford

1

Nine Elms

2

Three Bridges

2

Tunbridge Wells

1

 

Accidents and Incidents

  • 672 fell down a lift shaft to the Waterloo and City line at waterloo in 1948. It was cut up on the spot.

David Watkins was a photographer who got a job with the Southern Railway in their Film Unit at Waterloo Station. He recalls-

“I began my career with chronological exactness on the first of January 1948 (in those days a holiday only in Scotland) and three months later, on April 13th, shot my first piece of film. All the others were out on a job and I was left guarding the unit’s sanctum. Close by was a hydraulic lift by which rolling stock from the Waterloo and City underground was raised to the level of the main line for repairs. While some wagons were being shunted onto this device, the hydraulics gave out and dragged them plus the engine (M& class no 672) into the abyss. The driver and fireman jumped off just in time, while I , disturbed by the most almighty crash and thundering, grabbed a Newman Sinclair and shot some stuff of no 672 looking like an upside-down Hornby toy at the bottom of the lift shaft.

When the others came back everyone was pleased and excited until word came down from above that my negatives must be destroyed unprocessed – an early lesson for me that truth is seldom welcome in official circles”.

He went on to be an Oscar winning cinematographer.

  • An early incident involving an ‘’M7’’ Tank occurred on 6th March 1898, when No. 252 suddenly left the rails two miles north of Tavistock station, Devon. It was hauling the 5:30 PM Exeter to Plymouth service at an estimated 40 mph. Trailing the engine were seven vehicles (a covered carriage truck; two third class carriages; two guard’s vans; two bogie composites), which also derailed, and the formation came to a stop after travelling 210 yards through the ballast. There were no injuries to passengers or the crew, but the carriages sustained slight damage; in addition, the engine had its brake gear torn off. A Board of Trade report concluded that the cause of the accident was obscure and no single explanation for it was forthcoming. It was noted that the locomotive was brand new in June 1897, the carriages had recently been overhauled, and the route itself was of recent origin, too. No faults were detected in the engine’s wheels or springs during examination after the incident. However, previous experience had shown that whilst these engines were good hill climbers, they became unstable at speed when travelling downhill with slack couplings, and had a severe effect on the track. Given that the train had been travelling downhill, it was suspected that it had been running at a speed far greater than the 40 mph quoted by the driver.
    As a result class M7 locomotives were withdrawn from these duties.
  • On 25 May 1933, locomotive 107 was hauling a passenger train when it was derailed atRaynes Park, London, coming to rest foul of an adjacent line. Another passenger train was in a side-long collision with it. Five people were killed and 35 were injured. The accident was caused by a failure to implement a speed restriction on a section of track under maintenance.
  • On 27 November 1962, locomotive 30131 was derailed atEastleigh after it was moved by an unauthorised person.

General withdrawals commenced in 1957, with 30042 disappearing in June of that year. At this time, the type was spread throughout the Southern Region, allocated to every ‘’A’’ shed bar those of the South Eastern Division. Their demise gathered a pace thereafter, and in 1959 M7s were ousted from Waterloo pilot duties. They were replaced by a mixture of 0-6-0 WR Pannier and BR Standard 2-6-4 Tanks. On the advent of the 1960s, push-pull workings were rapidly decreasing as branch lines completely lost their services or, for those which retained trains, were dieselised. By May 1964 just nine M7 tanks remained in service, all of which were withdrawn during that month.

Preservation

Back to SR

Back to Locomotives