Caledonian 4-4-0 Locomotives in Great_Britain


Class Details by Steve Llanso of Sweat House Media

Class 1 (Locobase 5531)

Jim Smellie's article on this class appears as part of a series carried on a brass-locomotive modeling site -- [] (visited 13 May 2003).

John Lambie's design was built for use on the Lanarkshire and Dumbartonshire Railway and on the Glasgow Central, the latter featuring an underground section that led to the installation of steam condensing gear. He modified an Drummond boiler design (already tweaked by Smelllie), moving the steam dome forward and the safety valve stand back while using smaller-diameter tubes. The cylinders were a new design using undivided ports.

The condensers proved very unpopular with the crew because the water they dumped back into the tanks was too hot for the injectors and pumps to use. Still, the apparent benefits in swallowing the steam rather than venting it to the atmosphere underground led to the gear's retention for decades.

The class served the Maryhill-Airdrie runs, which amounted to 39 trains each way each day. They continued until the late 1920s-early 1930s, travelling about 25,000 miles/year/locomotive on average (which included a yearly average of 39,000 miles a year for #6 from its introduction to its boiler renewal in 1916).


Class 113 Dunalistair V (Locobase 20315)

Data from "New Express Passsenger Locomotive, Caledonian Railway", Locomotive Magazine, Volume 22, No 285 (15 May 1916). The Caledonian's own St Rollox Works produced the first six in 1916. In the same year, the North British Locomotive Works supplied a ten more (works numbers were 21442-21451 in 1916).

These are the first sixteen of a class of 48 Eight-wheelers that first emerged in 1916. Locomotive superintendent William Pickersgill supplied the information and a photograph. A full description of the post-war set of 32 appears in Locobase 2326. As noted in that entry, all of the motion was installed inside the frames, including the 9"(229 mm) piston valves and the cylinders as well.


Class 125 (Locobase 10647)

Data from "Connor's Bogie Engines, Caledonian Ry" The Locomotive Magazine, Vol XIV (15 April 1908), p.65. Boiler pressure is an estimate.

The LM report gives us two key points about this class designed by Benjamin Connor. First, it was the first bogie express class in service on the Caledonian and its very tall drivers confirm its high-speed intentions. Second, its boiler proved too small to ever be other than "very partial successes" on the Carlisle main line serving the North. They were, according to LM, "never able to hold their own with the famous 8-ft singles [Locobase 2205] running in the same service."

Drummond took the class in hand in 1886 and fitted them with larger boilers and placed them at the head of Glasgow-Dundee trains. "Upon this traffic they performed excellent service," says the report, "working practically all the express trains between these cities until 1897." Then they served boat trains between Glasgow Central and Adrossan until they were retired.


Class 139 (Locobase 15968)

Data from "Passenger Locomotive with Superheater, Caledonian Railway", The Locomotive, Volume 16 (15 August 1910), p. 159.

These were the first superheated locomotives in Scotland and their dimensions impress this North American.

Taking much from the Dunalastair IVs (Locobase 9426), McIntosh James McIntosh made sure to make room for a considerable amount of superheat. (The pyrometer gauge at working temperature showed 670 deg F.) Like many early superheater installations, however, the Caledonian reduced boiler pressure to decrease maintenance costs. McIntosh placed the piston valves over the cylinders, which allowed him to use the same valve settings as in the 140.

Sources differ on the number built and whether the 1912 engines saw a reduction in superheater area. See Locobase 2285 for the 1912 conversion of the Dunalastair IV class, which had similar dimensions to the 139s, but a smaller superheater.


Class 66 (Locobase 2236)

Data from J. Pearson Pattison, British Railways: Their Passenger Services, ... (London: Cassell & Co, 1893), p 135. Neilson delivered the first 10; their works numbers were 3058-3067. St Rollox delivered the last 6 in 1885.

This represented Dugald Drummond's essay in the four-coupled bogie for the Caledonian. A Dubs-built engine with novel Bryce-Douglas Valve Gear appeared at the 1884 Edinburgh Exhibition together the bogie single #123. The valve gear was not a success and this locomotive was rebuilt as a standard bogie passenger engine.


Class 72/3P (Locobase 2326)

Data from E C Poultney, "Recent Locomotive Practice on the Caledonian Railway - Part I", Engineer, Volume 132 (11 November 1921), pp. 499-500. The Caledonian's own St Rollox Works produced the first ten in 1920. Armstrong Whitwork works numbers 111-120 followed in 1921, and the North British Locomotive Works supplied a dozen more (works numbers 22943-22954 in 1922.

The accompanying photograph for the Engineer report on Caledonian locomotives shows this Pickersgill design to be something of a throwback, at least visually. Yes, there's a superheater (albeit of modest proportions and smaller than McIntosh's 1912 Dunalistair IVs shown in Locobase 2285), but the cylinders, their crossheads and connecting rods, the 9: (229 mm) diameter piston valves are all out of sight inside the frames. Moreover, the classic British plate frame construction extends even to the leading bogie. The lead adhesion drivers have their own splashers, the cab seems meager, the dome small, and the safety valve stand discreet.

Although Poultney noted the "rather high boiler demand and grate factors", he also commented on the relatively large firebox and grate. In comparing equal steaming rates, he suggested that the 4-4-0s "should furnish more steam per square foot of heating surface, or, in other words, stam more freely than the [Caledonian's] 4-6-0 locomotives." As an argument for why a factor of adhesion of 4.15 in these engines should be seen as low, Poultney offers: "I may say that whenever I have seen these engines starting with anything like a load, the steam sanders have always been in operation."


Class Dunalastair I (Locobase 2257)

Data from Edward Cecil Poultney, British Express Locomotive Development (London: George Allen and Unwin, 1952), pp. 29-33.

James McIntosh's essay in the Four-Coupled Bogies for the Caledonian was derived from John Lambie's immediately prior Eight-wheeler (Locobase 10805). He provided a larger boiler however by increasing both number of tubes and the diameter of each. Poultney argued that this led to a freer-steaming boiler, but perhaps at the expense of overheating the smokebox.

McIntosh's design quickly put up some impressive numbers. In one 1896 run, 721 reached speeds of 73.8, 76.3, and 79 mph in the 7 1/2 miles between Abington and Lamington. Charles Rous-Marten, who reported this performance, commented that the engine was worked well within its power.


Class Dunalastair II (Locobase 1111)

Striking, powerful engines that set the tone for British 4-4-0s, although not in a linear way. Belgian State Railways also bought 5.

Aka the "Breadalbane" class, this set of 15 locomotives built on the success of the Dunalastair Is (Locobase 2257) with slightly larger boilers.


Class Dunalastair III (Locobase 3751)

Further elaboration of the Dunalstair design of Dugal Drummond. This batch featured a larger grate than the IIs. Data from Jim Smellie's article on the 900 class gives the heating surface as shown in the specs. Further information from Jim McDonnell in a contribution to Bryan Attewell ([] Steam locomotive simulator (April 2000 edition) and from the Railroad Gazette (26 January 1900).

Smellie notes that five of the 16 were later superheated with Consolidated superheaters, the boiler then containing 159 1 3/4" tubes and 18 5" tubes. (The latter had, says Smellie, "long return loops and a hand-controlled damper".) 1,094.3 sq ft of tube heating surface was joined by 214 sq ft of superheater; firebox heating surface stayed the same. Slightly smaller, 18 1/2" pistons with 8" piston valves were added while boiler pressure was dropped to 170 psi. The class ran until the late 1930s for the most part, although a few lasted until just before nationalization in 1948.


Class Dunalastair IV (Locobase 9426)

Produced by JF McIntosh as an extension of earlier designs. The October 1905 Railway Engineer (pp.291-294) showed the original boiler layout that had an unusual mixture of 255 1 3/4" tubes and 21 2" tubes. See also A T Taylor, Modern British Locomotives (London: E & FN Spon, Ltd, 1907), p. 4.

The RE report notes that the East Coast corridor vestibule trains normally had 19 to 21 coaches that aggregated 350-400 tons. Behind the IVs, speeds frequently averaged 45-50 mph and the class needed assistance only on the long (9.75 miles/15.7 km) Beattock incline which had an average gradient of 1.33% (1 in 75).

See Locobase 2285 for the superheated upgrade that significantly reduced coal usage.


Class Dunalastair IV - superheated (Locobase 2285)

Data from "4-4-0 Express Passenger Engines, Caledonia Railway", Railway Engineer, Volume 34, No 6 (June 1914), pp. 173-175.

Produced by JF McIntosh as an extension of earlier designs. The October 1905 Railway Engineer showed the Dunalastair IV's original boiler layout (Locobase 9426) had an unusual mixture of 255 1 3/4" tubes and 21 2" tubes. The report notes that the East Coast corridor vestibule trains normally had 19 to 21 coaches that aggregated 350-400 tons. Behind the IVs, speeds frequently averaged 45-50 mph and the class needed assistance only on the long (9.75 mile/15.7-km) Beattock incline which had an average gradient of 1.33% (1 in 75).

Adding the superheater also meant fitting the design with 8" (203 mm) piston valves. According to OS Nock (RWC III, pl 77), superheating the Dunalstair IV led to some "striking economies." Whereas the saturated-steam version had to recoal at Carlisle during the 300-mile Perth-Carlilse-Perth round trip, these superheated engines needed one tender's worth to pull the heavy and fast trains on this run.


Class Lambie design (Locobase 10805)

Data from Edward Cecil Poultney, British Express Locomotive Development (London: George Allen and Unwin, 1952), pp. 29-33.

Although similar in power dimensions to the Dunalastairs that would follow shortly (see, e.g., Locobase 2257), John Lambie's engine had a smaller boiler that inevitably limited its steaming ability. It was the last design to appear before Lambie's sudden death on 1 February 1895 and the only one that would qualify as an express locomotive.

Half the class was retained for service on the LMS (London, Midland & Scottish) when that group began operations in 1923.

Principal Dimensions by Steve Llanso of Middle Run Media

Class1113 Dunalistair V12513966
Locobase ID5531 20315 10647 15968 2236
RailroadCaledonianCaledonianCaledonianCaledonianCaledonian
CountryGreat BritainGreat BritainGreat BritainGreat BritainGreat Britain
Whyte4-4-0T4-4-04-4-04-4-04-4-0
Number in Class121651016
Road Numbers1-12113-116, 121, 124, 928-937/14461-14476/54461-54476125-129139, 132-135, 117-122/14440-1444966-75, 60-65
GaugeStdStdStdStdStd
Number Built121651016
BuilderSt. RolloxseveralNeilson & CoSt. Rolloxseveral
Year18911916187719101884
Valve GearStephensonStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)9 / 2.74 9.75 / 2.97 8.58 / 2.62 9.75 / 2.979 / 2.74
Engine Wheelbase (ft / m)24.83 / 7.5724.33 / 7.4221.21 / 6.4623.83 / 7.2622.10 / 6.74
Ratio of driving wheelbase to overall engine wheelbase 0.36 0.40 0.40 0.41 0.41
Overall Wheelbase (engine & tender) (ft / m)24.83 / 7.5746.90 / 14.30
Axle Loading (Maximum Weight per Axle) (lbs / kg)44,576 / 20,21933,040 / 14,98734,160 / 15,495
Weight on Drivers (lbs / kg)78,148 / 35,44789,040 / 40,38863,504 / 28,80568,096 / 30,888
Engine Weight (lbs / kg)112,756 / 51,145137,200 / 62,23392,624 / 42,014132,160 / 59,947101,136 / 45,875
Tender Loaded Weight (lbs / kg)104,160 / 47,24661,376 / 27,840125,440 / 56,89978,400 / 35,562
Total Engine and Tender Weight (lbs / kg)112,756 / 51,145241,360 / 109,479154,000 / 69,854257,600 / 116,846179,536 / 81,437
Tender Water Capacity (gals / ML)1200 / 4.555040 / 19.091880 / 7.125520 / 20.913420 / 12.95
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.20 / 2 6.60 / 6 3.30 / 3 7.70 / 7
Minimum weight of rail (calculated) (lb/yd / kg/m)65 / 32.5074 / 3753 / 26.5057 / 28.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)60 / 152478 / 198186 / 218478 / 198178 / 1981
Boiler Pressure (psi / kPa)150 / 10.30180 / 12.40130 / 9.70165 / 11.40160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)17" x 24" / 432x61020" x 26" / 508x66018" x 24" / 457x61020" x 26" / 508x66018" x 26" / 483x660
Tractive Effort (lbs / kg)14,739 / 6685.5120,400 / 9253.309991 / 4531.8518,700 / 8482.1914,688 / 6662.37
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.30 4.36 6.36 4.64
Heating Ability
Tubes (number - dia) (in / mm)224 - 1.625" / 41157 - 1.75" / 44163 - 1.75" / 44226 - 1.75" / 44
Flues (number - dia) (in / mm)24 - 5" / 12724 - 5" / 127
Flue/Tube length (ft / m)10.33 / 3.1511.50 / 3.5111.50 / 3.51
Firebox Area (sq ft / m2)111 / 10.32145 / 13.4782 / 7.62145 / 13.47122 / 11.34
Grate Area (sq ft / m2)17 / 1.5820 / 1.8614.60 / 1.3621 / 1.9519.50 / 1.81
Evaporative Heating Surface (sq ft / m2)1096 / 101.861365 / 126.81987 / 91.691365 / 126.811210 / 112.45
Superheating Surface (sq ft / m2)295 / 27.41330 / 30.66
Combined Heating Surface (sq ft / m2)1096 / 101.861660 / 154.22987 / 91.691695 / 157.471210 / 112.45
Evaporative Heating Surface/Cylinder Volume173.83144.39139.63144.39158.01
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation25503600189834653120
Same as above plus superheater percentage25504248189841233120
Same as above but substitute firebox area for grate area16,65030,79810,66028,47119,520
Power L1392811,745368311,4814944
Power MT221.62581.61255.72320.13

Principal Dimensions by Steve Llanso of Middle Run Media

Class72/3PDunalastair IDunalastair IIDunalastair IIIDunalastair IV
Locobase ID2326 2257 1111 3751 9426
RailroadCaledonianCaledonianCaledonianCaledonianCaledonian
CountryGreat BritainGreat BritainGreat BritainGreat BritainGreat Britain
Whyte4-4-04-4-04-4-04-4-04-4-0
Number in Class3215151619
Road Numbers72-91, 66-71, 92-97/14477-14508/54467-54508721 / 14311-14325766887-902140
GaugeStdStdStdStdStd
Number Built3215151619
BuilderNorth BritishSt. RolloxSt. RolloxSt. RolloxSt. Rollox
Year19201896189718991905
Valve GearStephensonStephensonJoy
Locomotive Length and Weight
Driver Wheelbase (ft / m) 9.75 / 2.979 / 2.749 / 2.74 9.50 / 2.90 9.75 / 2.97
Engine Wheelbase (ft / m)24.33 / 7.4223.08 / 7.0323.08 / 7.0323.58 / 7.1923.83 / 7.26
Ratio of driving wheelbase to overall engine wheelbase 0.40 0.39 0.39 0.40 0.41
Overall Wheelbase (engine & tender) (ft / m)46.9049.46 / 15.08
Axle Loading (Maximum Weight per Axle) (lbs / kg)44,57641,412 / 18,784
Weight on Drivers (lbs / kg)89,040 / 40,38870,000 / 31,75277,616 / 35,20679,968 / 36,27380,248 / 36,400
Engine Weight (lbs / kg)137,200 / 62,233105,213 / 47,724118,328 / 53,673115,808 / 52,530121,800 / 55,248
Tender Loaded Weight (lbs / kg)104,160100,800 / 45,72287,528100,800 / 45,722118,664 / 53,825
Total Engine and Tender Weight (lbs / kg)241,360 / 62,233206,013 / 93,446205,856 / 53,673216,608 / 98,252240,464 / 109,073
Tender Water Capacity (gals / ML)50404284 / 16.234950 / 15.633570 / 13.525160 / 19.55
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 6.607 / 65 / 55 / 5
Minimum weight of rail (calculated) (lb/yd / kg/m)74 / 3758 / 2965 / 32.5067 / 33.5067 / 33.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)78 / 198178 / 198178 / 198178 / 198178 / 1981
Boiler Pressure (psi / kPa)180 / 12.40160 / 11175 / 12.10200 / 13.80180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)20.5" x 26" / 521x66018.25" x 26" / 464x66019" x 26" / 483x66019" x 26" / 483x66019" x 26" / 483x660
Tractive Effort (lbs / kg)21,433 / 9721.8615,099 / 6848.8017,900 / 8119.3120,457 / 9279.1518,411 / 8351.10
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.15 4.64 4.34 3.91 4.36
Heating Ability
Tubes (number - dia) (in / mm)157 - 1.75" / 0265 - 1.75" / 44265 - 1.75" / 44269 - 1.75" / 44255 - 1.75" / 44
Flues (number - dia) (in / mm)24 - 5" / 021 - 2" / 51
Flue/Tube length (ft / m)11.50 / 4.9510.58 / 3.2211.33 / 3.4511.33 / 3.4511.50 / 3.51
Firebox Area (sq ft / m2)144 / 13.38118.78 / 11.04118.70 / 11.03138 / 12.83145 / 13.47
Grate Area (sq ft / m2)20.70 / 1.9220.63 / 1.9220.60 / 1.9123 / 2.1421 / 1.95
Evaporative Heating Surface (sq ft / m2)1329 / 123.511403 / 130.391500 / 139.411600 / 148.701615 / 150.04
Superheating Surface (sq ft / m2)200 / 18.59
Combined Heating Surface (sq ft / m2)1529 / 142.101403 / 130.391500 / 139.411600 / 148.701615 / 150.04
Evaporative Heating Surface/Cylinder Volume133.80178.23175.81187.53189.28
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation37263301360546003780
Same as above plus superheater percentage42103301360546003780
Same as above but substitute firebox area for grate area29,29019,00520,77327,60026,100
Power L190685276558269786418
Power MT449.05332.33317.10384.75352.64

Principal Dimensions by Steve Llanso of Middle Run Media

ClassDunalastair IV - superheatedLambie design
Locobase ID2285 10805
RailroadCaledonianCaledonian
CountryGreat BritainGreat Britain
Whyte4-4-04-4-0
Number in Class6
Road Numbers12013 / 14308-14310
GaugeStdStd
Number Built6
BuilderSt. RolloxSt. Rollox
Year19121894
Valve GearJoyStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 9.75 / 2.979 / 2.74
Engine Wheelbase (ft / m)23.83 / 7.2622.08 / 6.73
Ratio of driving wheelbase to overall engine wheelbase 0.41 0.41
Overall Wheelbase (engine & tender) (ft / m)44.46 / 13.55
Axle Loading (Maximum Weight per Axle) (lbs / kg)43,568 / 19,762
Weight on Drivers (lbs / kg)85,120 / 38,61068,500 / 31,071
Engine Weight (lbs / kg)133,280 / 60,455101,360 / 45,976
Tender Loaded Weight (lbs / kg)87,472 / 39,677
Total Engine and Tender Weight (lbs / kg)188,832 / 85,653
Tender Water Capacity (gals / ML)4284 / 16.23
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)71 / 35.5057 / 28.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)78 / 198178 / 1981
Boiler Pressure (psi / kPa)170 / 11.70160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)20.25" x 26" / 514x66018" x 26" / 457x660
Tractive Effort (lbs / kg)19,751 / 8958.9114,688 / 6662.37
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.31 4.66
Heating Ability
Tubes (number - dia) (in / mm)163 - 1.75" / 44238 - 1.625" / 41
Flues (number - dia) (in / mm)24 - 5" / 127
Flue/Tube length (ft / m)11.50 / 3.5110.58 / 3.22
Firebox Area (sq ft / m2)145 / 13.47112.62 / 10.47
Grate Area (sq ft / m2)21 / 1.9519.50 / 1.81
Evaporative Heating Surface (sq ft / m2)1365 / 126.811184 / 110.04
Superheating Surface (sq ft / m2)295 / 27.41
Combined Heating Surface (sq ft / m2)1660 / 154.221184 / 110.04
Evaporative Heating Surface/Cylinder Volume140.84154.62
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation35703120
Same as above plus superheater percentage42133120
Same as above but substitute firebox area for grate area29,08718,019
Power L110,8204746
Power MT560.48305.49

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