class 24 class 25 details
Basic Details
Class 24 & 25

Particulars for both Class 24 & 25

Wheel arrangement: Bo-Bo
Length over buffers: 50ft 6in
Height over cowl: 12ft 8in
Width: Class 24 - 9ft 1.375in; Class 25 - 8ft 1.625in
Total Wheelbase: 36ft 6in
Bogie Wheelbase: 8ft 6in
Bogie Pivot Centres: 28ft 0in
Minimum curvature: 4.5chains (297ft) radius
Length over buffers: 50ft 6in
Wheel Diameter: 45in

Class 24

Total Built: 151
Builders: British Railways Workshops:

Derby: 5000 - 5029, 5066 - 5075, 5114 - 5150
Crewe: 5030 - 5065, 5076 - 5093
Darlington: 5094 - 5113
Delivered: August 1958 - February 1961
Service Life: August 1958 - October 1980
Traction Motor Gear Ratio: 81 : 16
Engine Continuous Rating: 1,160hp at 750rpm
Power absorbed by auxiliaries (average): 65bhp
Maximum Tractive Effort at rail: 40,000lbs (24.2% adhesion)
Maximum Current: 2,340amps
Continuous Tractive Effort at rail: 21,300lbs at 16.5 mph
Continuous Generator rating: 720kW, 525 volts, 1,400 amps; 750 volts 980 amps
Maximum Speed: 75 mph
Fuel Tank Capacity D5000 - D5049: 630 gallons
Fuel Tank Capacity D5050 - D5150: 520 gallons
Auxiliary Fuel Tank Capacity D5000 - D5049: 20 gallons
Auxiliary Fuel Tank Capacity D5050 - D5150: 10 gallons
Boiler Water Capacity D5000 - D5049: 600 gallons
Boiler Water Capacity D5050 - D5150: 520 gallons
Cooling Water Pressure (engine running): 15 lb/sq in
Water Temperature: max 185F, normal 165F - 175F
Lubricating Oil Capacity: 100 gallons
Lubricating Oil Temperature: max 185F, normal 160F - 170F
Engine Oil Pressure (full power): 50 lb/sq in
Charging Air Pressure (full power): 9-12 lb/sq in
Exhaust Temperature: All cylinders to be within 100F of each other
Engine: Sulzer 6LDA28A pressure-charged four stroke
Main Generator: AEI Type RTB 15656
Traction Motors: 4 x AEI Type 137BY or BX
Steam Generator D5000 - D5003: Type OK4616A
Steam Generator D5004 - D5043: Type OK4616B
Steam Generator D5044 - D5150: Type L4610

Two rung bogie mounted footsteps from new: 5000 - 5029 (Derby), 5030 - 5049 (Crewe 5040 & 5047 assumed - can't find early photo), (but liable to change later as locomotives received repairs), (review incomplete).
Ridge sided sandboxes from new: 5000 - 5150 (but liable to change later as locomotives received repairs).
Athermos axleboxes from new: 5010 - 5019.
Gangway doors never removed: 24016, 24021, 24027, 24031, 24033, 24059, 24085, 24090, 24144, 24146
Gangway doors partially removed: 24041 No.1 cab removed, 24049 No.2 cab removed.
Modified Headcode boxes - with sloped sides: 24147 (both cabs), 24148 (both cabs)
Modified Headcode boxes - Class 24/1 style : 24049 (No.2 cab)
Livery: two numbers & two emblems each side (from 1967 - 1968 shoppings): 5025, 5028, 5049, 5106, 5113, 5139, 5146, 5150
Water tank removed: 24032, 24039, 24081
Original exhaust port covered but not immediately removed: 5059
Tanks: full size fuel & water:
Tanks: fuel tank lowered & full size water: 5059

Class 25

Total Built: 327
Builders: British Railways Workshops: Derby, Darlington; and Beyer Peacock Ltd, Manchester

Darlington: 5151 - 5185, 5223 - 5232, 7578 - 7597
Derby: 5186 - 5222, 5233 - 5299, 7500 - 7577, 7598 - 7623, 7660 - 7677
Beyer Peacock: 7624 - 7659
Delivered: April 1961 - May 1967
Service Life: April 1961 - March 1987
Traction Motor Gear Ratio 25001 - 25025: 79 : 18
Traction Motor Gear Ratio 25026 - 25327: 67 : 18
Engine Continuous Rating: 1,250hp at 750rpm
Power absorbed by auxiliaries (average): 65bhp
Maximum Tractive Effort at rail 25001 - 25025: 39,000lbs
Maximum Tractive Effort at rail 25026 - 25327: 46,500lbs
Maximum Current 25001 - 25025: 2,525amps
Maximum Current 25026 - 25327: 2,640amps
Continuous Tractive Effort at rail: 20,500lbs at 18 mph
Continuous Generator rating 25001 - 25025: 817kW, 750 volts, 1,090 amps; 545 volts 1,500 amps
Continuous Generator rating 25026 - 25327: 780 volts, 1,050 amps; 545 volts 1,500 amps
Maximum Speed: 90 mph
Fuel Capacity : 510 gallons
Boiler Water Capacity 25026 - 25028, 25033 - 25087, 25218 - 25247: 580 gallons
Lubricating Oil Capacity: 100 gallons, maximum on dipstick indicates 86 gallons
Coolant Capacity: 186 gallons
Water Temperature: max 185F, normal 165F - 175F
Engine: Sulzer 6LDA28B pressure-charged four stroke
Main Generator: AEI Type RTB 15656
Auxiliary Generator: AEI Type RTB 7440
Traction Motors 25001 - 25025: 4 x AEI Type 137BY or BX
Traction Motors 25026 - 25327: 4 x AEI Type 253AY
Traction Motor Rating 25026 - 25327: 650 amps at 315 volts
Traction Motor Gear Ratio: 67 : 18
Steam Generator 25026 - 25028, 25033 - 25087, 25218 - 25247: Stone Vapor L4610
Weight in Working Order 25026 - 25028, 25033 - 25082, 25218 - 25247: 73 tons 15cwt
Weight in Working Order 25029 - 25032: 71 tons 9cwt
Weight in Working Order 25083 - 25087: 73 tons 1cwt
Weight in Working Order 25088 - 25217, 25248 - 25327: 70 tons 14cwt
Maximum Axle Loads 25026 - 25028, 25033 - 25082, 25218 - 25247: 18 tons 17cwt
Maximum Axle Loads 25029 - 25032: 18 tons 5cwt
Maximum Axle Loads 25083 - 25087: 18 tons 12cwt
Maximum Axle Loads 25088 - 25217, 25248 - 25327: 18 tons 1cwt

Livery: carried green livery with TOPS numbering: 25036, 25043, 25102, 25218, 25252, 25261, 25294.
Livery: two numbers & two emblems each side (from 1967 - 1968 shoppings): 5151, 5161, 5164, 5165, 5166, 5167, 5168, 5172, 5223, 5283, 7562, 7572, 7661, 7662, 7663, 7664, 7665, 7666, 7667, 7668, 7669, 7671, 7672, 7673, 7674, 7675, 7676, 7677
Livery: large bodyside number (ex-Glasgow): 25046, 25062, 25065, 25075, 25083, 25084, 25085, 25086, 25109, 25226, 25230, 25231, 25234
Livery: number on bodyside (ex-Glasgow): 25001, 25005, 25006, 25007, 25009, 25010, 25011, 25013, 25021, 25026, 25033, 25034, 25035, 25044, 25049, 25050, 25059, 25062, 25064, 25068, 25072, 25075, 25076, 25078, 25079, 25082, 25086, 25087, 25090, 25091, 25093, 25094, 25098, 25099, 25108, 25125, 25130, 25140, 25144, 25149, 25153, 25156, 25162, 25171, 25172, 25188, 25202, 25216, 25227, 25228, 25229, 25232, 25233, 25235, 25237, 25239, 25240, 25241, 25244, 25246, 25247, 25266, 25283, 25286, 25296, 25300, 25306, (25904, 25905, 25906)
Livery: tablet catcher recesses sheeted over: 25262, 25266, 25270 (No.1 cab only), 25272 (No.2 cab only)
Modified Headcode boxes - with sloped sides: 25009 (No.1 cab only)
Modified Headcode boxes - Class 25/1 style (with horn receptacles): 25010 (No.1 cab only)
Royal Train cabling modification: 25222.
Sheeted over Boiler Room Grilles: 25101, 25102, 25105, 25110, 25111, 25112, 25114, 25116, 25123, 25124, 25126, 25131, 25132, 25133, 25137, 25138, 25141, 25142, 25143, 25146, 25148, 25150, 25152, 25158, 25160, 25161, 25163, 25164, 25165, 25166, 25167, 25168, 25169, 25170, 25180, 25186, 25195, 25211, 25214, 25215, 25263, 25270, 25274, 25280, 25281, 25294, 25302
Non-standard Battery Isolating Switch Cover - three circular hinged discs: 25066, 25215, 25228, 25232
Gangway doors never removed: 25015, 25029, 25045.
Boiler Water Tank removed: 25242.
Center lampbracket & other fittings removed : 25032 (No.2 cab only lamp bracket present other fittings removed), 25036, 25042, 25046, 25049, 25051 (No.1 cab only), 25059, 25061, 25062, 25064, 25068, 25071, 25072, 25073, 25076, 25079, 25081, 25082, 25115 (No.2 cab only lamp bracket present other fittings removed), 25204 (No.2 cab only), 25218, 25223, 25224 (No.2 cab only), 25225, 25226, 25227, 25228, 25231, 25232, 25233, 25234, 25235, 25239, 25240, 25241, 25242, 25244, 25246, 25247, 25262 (No.2 cab only lamp bracket present other fittings removed), 25270 (No.1 cab only), 25271 (No.2 cab only), 25272 (No.2 cab only), 25296 (No.2 cab only), 25305 (No.2 cab only), 25314 (No.2 cab only), 25316 (No.1 cab only).
Class 25s with last Classified repair at Crewe: 25256, 25295, 25304.
Angled strip at bottom of cab doors: 25076, 25130, 25144, 25188, 25286, 25296.

Sources:
Operating Manual British Railways Locomotives D5000 - D5175; dated January 1962
Operating Manual British Railways Locomotives D5176 - D5299, D7500 - D7677; dated July 1966

Page added May 16th 2011
Last updated March 20th 2017

Return to Picture menu
Return to Home page