British Rail Class 24

Infobox Locomotive
name = British Railways Type 2
British Rail Class 24
powertype = Diesel-elctric

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caption = An unidentified Class 24 at Mossend yard in September 1976.
roadnumber = D5000–D5150; later 24001–24047, 24051–24141
builder = British Railways’ Derby Works, Darlington Works and Crewe Works
builddate = 1958–1961
totalproduction = 151
gauge = RailGauge|ussg|lk=on|al=on
primemover = Sulzer 6LDA28
generator = BTH RTB15656
tractionmotors = BTH 137BY, 4 off
transmission = DC generator, DC traction motors
whytetype = Bo-Bo
uicclass = Bo'Bo'
wheeldiameter = convert|3|ft|9|in|m|3|abbr=on
minimumcurve = convert|4.5|chain|m|lk=in
trainbrakes = Vacuum
locobrakeforce = convert|38|LTf|kN|abbr=on|lk=in
wheelbase = convert|36|ft|6|in|m|2|abbr=on
length = convert|50|ft|6|in|m|2|abbr=on
width = convert|8|ft|10|in|m|2|abbr=on
height = convert|12|ft|8|in|m|2|abbr=on
weight = "Class 24/0:" convert|79|LT|sigfig=3
"Class 24/1:" convert|73|LT|sigfig=3
topspeed = convert|75|mph|abbr=on|lk=on
poweroutput = "Engine:" convert|1160|hp|0|abbr=on|lk=on
"At rail:" convert|843|hp|0|abbr=on
tractiveeffort = "Maximum:" convert|42000|lbf|kN|1|sigfig=3|abbr=on|lk=on
"Continuous:" convert|21300|lbf|kN|sigfig=3|abbr=on
fuelc
convert|546|impgal|abbr=on|lk=on
"Class 24/1:" convert|500|impgal|abbr=on
trainheating = Steam
multipleworking = ★ Blue Star
axleloadclass = "Class 24/0:" RA 7 (6 from 1969)
"Class 24/1:" RA 6 (5 from 1959)
railroad = British Railways
preservedunits = Four (list)
retiredate = 1967–1980The British Rail Class 24 diesel locomotives, also known as the Sulzer Type 2, were built from 1958-1961. One hundred and fifty-one of these locomotives were built at Derby, Crewe and Darlington, the first twenty of which were ordered as part of the 1955 British Rail modernisation plan. This class was used as the basis for the development of the Class 25 locomotives.

The final locomotive, no. 24081, was withdrawn from Crewe depot in 1980.

Technical details

Engine

The main power for the Class 24 was the Sulzer 6LDA28 diesel engine - denoting 6 cylinders; Locomotive use; Direct fuel injection; Abgasturbine (turbo-charged); convert|28|cm|in|abbr=on bore cylinders. This was effectively an off-the-shelf purchase with small changes to bearings, injectors and some other minor items.

Transmission

The diesel engine powered another off-the-shelf product, the British Thomson-Houston (BTH) RTB15656 main generator which, in the Class 24, was rated at convert|735|kW|abbr=on, 750/525 V and 980/1400 A at 750 rpm. Traction motors, one per axle, were also by BTH being the type 137BY rated at convert|222|hp|abbr=on, 525 V, 350 A at 560 rpm with a 16:81 gear ratio, each force ventilated by an AEI convert|12.2|hp|abbr=on electric motor.

Train heating

The original pilot scheme locos (D5000–D5019) were fitted with a Stone Vapour type OK4646A steam heating boiler with a 600 gallon water tank. The following ten locos had the similar convert|1750|lb per hour type OK4616B and a reduced water capacity of 450 gallons, and this was perpetuated in the remaining production run which used the Stone Vapour convert|1000|lb per hour type L4610 boiler. These variations meant that the initial batch of 20 locomotives tipped the scales at 79tons 16cwt; the following 10 locomotives slightly lower at 78 tons 14cwt; the remainder of the Class 24/0 at 77 tons; and the Class 24/1 at 73 tons exactly. During subsequent years the boilers were removed from the majority of Class 24/1 locomotives, reducing the overall weight by 2 tons. Ten locomotives (D5102–5111) had no train heating, the space being occupied by the air compressors needed for operation of the Consett iron ore trainscite book |last = Strickland, D. C. |title = Locomotive Directory, every single one there has ever been |publisher = Diesel and Electric Group | year = 1983 |location = Camberley, Surrey |isbn = 0 906375 10 X |pages = pp. 78–82]

Other systems

Several of the systems within the Class 24s were standard. The braking system was the standard BR system, adopted as part of the modernisation plan, of locomotive air and train vacuum brake, both applied by a single handle via a proportional valve. Similarly the connection for multiple working was the standard electro-pneumatic system designated "Blue Star" with each loco bearing a small blue coloured 5-pointed star above each buffer to denote this. Also common was the provision of a door to allow staff to pass between locomotives, or between a locomotive and adjacent coach. In practice these were rarely used and were sealed shut at overhaul during the 1970s to reduce draughts in the cab.

With production reaching 151, there were some differences between batches of locos too. 10 of the initial 20 had "Athermos" pressure-lubricated plain bearing axleboxes rather than the more usual roller-bearing axleboxes. Although these remained for the life of the locos, they were the only ones so fitted. Much more noticeable were D5114–D5132 which were fitted with tablet catchers on the side of the drivers cab for use on the Far North Line from Inverness. Also very visible were the roof-mounted headcode boxes fitted from D5114 giving an outward appearance very similar to the later Class 25 but without horn grilles.

Liveries

The pilot scheme locomotives were delivered in overall green livery with a grey roof and black below the body. D5000 was delivered with a narrow white stripe at waist level while the remainder sported a broad white stripe at solebar level. At first green liveried locos had plain green ends, but this was changed later to small yellow warning panels, and then to full yellow end, some locos receiving these while still in green livery. At least one loco, D5005, is recorded in 1966 as having two-tone green livery applied along with the small yellow warning panel in a similar manner to Class 47s and some Class 25scite book | last = Kennedy | first = Rex | title = Diesels and Electrics on Shed Volume 1 - London Midland Region | publisher = Oxford Publishing Co | year = 1979 | location = Oxford |page = Plate 62| isbn = 0 86093 035 1.

Operation

While initial delivers were for operation in the Crewe and Derby areas, 15 of the initial 20 were diverted for use on the Southern Region where the Kent Coast Electrification project was delayed. Here the heavy weight was not acceptable and the locos in question had to have their boilers removed before they were accepted. Later some locos had their boilers re-fitted and these could be found, often in tandem with a Class 33 to provide steam heating to the coaches, the 33s only having electric train heat (ETH).

As deliveries continued, allocations were made to both the London Midland Region and Eastern Region, and with the class becoming familiar to crews and staff around London they were used on freights over the Metropolitan Widened Lines, locos so used being fitted with London transport tripcocks, although these were removed after closure of this route in 1971. Locos allocated to East Anglia for use on freights soon became redundant due to the run down of freight in that region, and these were in turn moved to Wales and Lancashire.

The batch D5096–D5113 were all allocated to Gateshead depot in 1966 to replace 9F steam locos on the Tyne Dock to Consett iron ore trains. These used a special design of bogie hopper wagon, and these locos had an additional compressor and associated pipework. These workings, typically with loads of around 1,000 tons, were double-headed and continued until taken over by Class 37s in the 1970s, whence these locos were reallocated to Scottish depots. Incidentally D5096 was, when delivered in January 1960, the first main line diesel locomotive to be built at Darlington Workscite web | last = Turner | first = Graham | authorlink = | title = Rail Blue timeline | work = | publisher = | date = | url = http://www.railblue.com/timeline.htm | format = | doi = | accessdate = 2008-04-10.

The next batch of locos, D5114–D5132 were allocated to Inverness, and became synonymous with rail operations in the Scottish Highlands, as did a similar batch of Class 26 locos, the two being considered interchangeable in operation. Single Class 24s operated from Inverness on passenger and freight trains of up to 290 tons, and double-headed on trains up to 580 tons including the Royal Highlander which was regularly made up of 16 coaches. Class 24s and Class 26s were used turn and turn about until all Class 24s allocated to Inverness were replaced by Class 26s in 1975.cite web | last = Hills | first = David | authorlink = | coauthors = | title = DerbySulzers - 1975 | work = | publisher = | date = | url = http://www.derbysulzers.com/75.html | format = | doi = | accessdate = 2008-03-12.

The final batch of Class 24s were allocated to the London Midland Region for use on the "Western Lines" which covered North Wales and Mid Wales. In the latter area, particularly on the Ex-Cambrian Railway lines, Class 24s and the similar Class 25s were the only diesel types to be found, and crews from Aberystwyth shed were only trained on these typescite book | last = Perkins | first = Chris | coauthors = Oakley, Michael | title = BR Class 24/25 Diesels | publisher = Bradford Barton | year = 1982 | location = Truro | isbn = 0 85153 432 5.

Withdrawal

The very first Class 24 to be withdrawn was in November 1967 when a fire broke out on D5051 while it was working a train of empty coal wagons in Scotland. The damage was too severe for it to be repaired, and it was cut up at Inverurie in August 1968cite web | last = Hills | first = David | authorlink = | coauthors = | title = DerbySulzers - 1967 | work = | publisher = | date = | url = http://www.derbysulzers.com/67.html | format = | doi = | accessdate = 2008-03-12cite book | last = Taylor | first = Ken | title = A Decade After | publisher = Midland Railfans | location = Walsall . It had lasted exactly 8 years. The second Class 24 to be withdrawn was also as the result of an accident in Scotland, this time at Castlecary. In this case D5122, running light engine, hit a stationary DMU at about convert|40|mph|abbr=on, the impact and subsequent fire bending the main frames and completely destroying the No.2 end. The accident happened on 9 September 1968 but despite being withdrawn the same month, the locomotive was not finally cut up until March 1971cite web | last = Hills | first = David | authorlink = | coauthors = | title = DerbySulzers - 1968 | work = | publisher = | date = | url = http://www.derbysulzers.com/68.html | format = | doi = | accessdate = 2008-03-12. A total of 14 Class 24s were withdrawn and scrapped without receiving their TOPS number.

Some Class 24s were withdrawn in 1973 with the closure of the Waverley route, which linked Carlisle and Edinburgh, but most of these were put into storage and subsequently re-entered traffic to fill gaps left by the movement of Class 25s to cover the withdrawal of Class 22s on the Western Region. Thus Class 24 withdrawals only started in earnest with completion of the Glasgow electrification in 1974, and re-allocation of Class 26 and Class 27 locos saw the Class 24s concentrated around various Lancashire depots and at Carlisle. On 27 November 1976 there were just 10 Class 24s still in operational service, all allocated to Crewe Diesel Depot (depot code CD)cite book | title = British Rail Locoshed Book 1977 | publisher = Ian Allen Ltd | location = Shepperton | isbn = 0 7110 0752 7.

By 1978 the last three operational locos were 24081, 24087 and 24133, even these managing to disgrace themselves on the Class 24 farewell railtour; working the train from Wolverhampton 24133 caused delays with electrical trouble affecting the multiple-working equipment and resulting in the two locos each requiring a crewcite web | last = Hills | first = David | authorlink = | coauthors = | title = DerbySulzers - 1978 | work = | publisher = | date = | url = http://www.derbysulzers.com/78.html | format = | doi = | accessdate = 2008-03-11. Later in the tour 24087 flashed over two traction motors, then finally suffered a main generator flashover on the return leg of the tour leaving a Class 25 to take the train back to Wolverhapton. 24133 had also taken part in the "Farewell to the 44s" railtour in January that year, providing steam heating for the coaches while 44008 "Penyghent" provided the motive powercite book | last = Vaughan | first = John | title = Double-headed diesels nationwide | publisher = OPC | year = 1980 | location = Oxford | page = Plate 240 | isbn = 0 86093 0815 .

The final recorded passenger duty of a Class 24 was on 29 April 1978 when 24047 took over the 16.00 Crewe - Cardiff when 25058 failed at Donington. The Class 24 proceeded to haul the train as far as Hereford where 47358 took over.

Cutting up of some Class 24s was carried out at Swindon Works on the BR Western Region, an area which had never received an allocation of Class 24s. The first locos were 24042, 24045, 24048 and 24050 which were moved from Derby Works in December 1975, and the last of the 67 Class 24s cut up at Swindon was 24078 in early December 1978cite book | last = Taylor | first = Ken | title = A Decade After (Appendix 1) | publisher = Midland Railfans | location = Walsall .

The very last Class 24 to be withdrawn from operational service was 24081.cite web | last = Hills | first = David | authorlink = | coauthors = | title = DerbySulzers - 24081 | work = | publisher = | date = | url = http://www.derbysulzers.com/24081.html | format = | doi = | accessdate = 2008-04-10 This loco, allocated to Crewe Diesel Depot (CD) had been considered something of a celebrity lasting over a year after the previous withdrawal of 24063 on 9 April 1979. 24081 was finally withdrawn in October 1980 having worked its last revenue earning train, the 05.43 Grange - Shotwick freight on 7 January 1980, and then making guest appearances at Nuneaton, Crewe Works Open Day, and Southport.

Departmental use

In November 1975 24061 was transferred to BRs research department based at Derby Works, and was allocated the number RDB968007. This loco was subsequently renumbered as 97201 and was finally withdrawn in 1984, the last Class 24 to be operational on BR.After withdrawal in 1976 two Class 24s were converted into train pre-heating units and were allocated to the Western Region: 24054 was withdrawn in August and became TDB968008, being allocated to Newton Abbot until withdrawn in October 1982; 24142 became TDB968009 and was allocated to Landorecite book | last = Marsden | first = Colin J. | title = Motive power recognition:1 Locomotives | publisher = Ian Allen Ltd | year = 1981 | location = Shepperton | isbn = 0 7110 1109 5cite book | title = British Rail Locoshed Book 1981 | publisher = Ian Allen Ltd | location = Shepperton | isbn = 0 7110 1112 5cite web | last = Hills | first = David | authorlink = | coauthors = | title = DerbySulzers - 1976 | work = | publisher = | date = | url = http://www.derbysulzers.com/76.html | format = | doi = | accessdate = 2008-03-12.

Preservation

Four locomotives have been preserved.

Accidents

D5002 was involved in the 1967 Stechford rail crash.cite web | last = Hills | first = David | authorlink = | coauthors = | title = DerbySulzers - Class 24 & Class 25 accidents | work = | publisher = | date = | url = http://www.derbysulzers.com/bent25.html | format = | doi = | accessdate = 2008-03-19.

D5122 was involved in a serious accident at Castlecary in 1968.

5028 was involved in the Chester General rail crash in 1972.

Gallery

References and Sources

References

ources

*cite book | last = Stevens-Stratten | first = S.W. | coauthors = Carter, R.S. | title = British Rail Main-Line Diesels | publisher = Ian Allen Ltd | year = 1978 | location = Shepperton | isbn = 0 7110 0617 2
*cite book | last = Williams | first = Alan | coauthors = Percival, David | title = British Railways Locomotives and Multiple Units including Preserved Locomotives 1977 | publisher = Ian Allen Ltd | year = 1977 | location = Shepperton | isbn = 0 7110 0751 9
*cite book | title = ABC of British Railways Locomotives, summer 1966 Edition | publisher = Ian Allen Ltd | year = 1966 |

External links

* [http://www.derbysulzers.com/ derbysulzers.com]
* [http://www.railwaysarchive.co.uk/documents/MoT_Castlecary1968.pdf Report on the crash at Castlecary on ] 9 September 1968]