Preserved Caledonian Railway '439' Class No. 419 leaving Shackerstone with the Footplate Experience service. Note the pronounced steam leak at the front end.
Following a previous problem, a gasket in the main steam pipe had been replaced and this was initially suspected as the cause of the new problem. However, when the locomotive had cooled sufficiently to determine the source of the leak, we found that the front left cylinder cover was the culprit. Nothing further could be done then, so I completed the day as 'second-man' on the Class 33 performing the last passenger round trip of the day. I subsequently learnt that, once cold, the cylinder cover had been successfully tightened up and the locomotive restored to traffic. Apparently, this locomotive has a history of this problem reccurring periodically.
Limited access to the cylinders and valve chest front covers is via the hinged 'piano front' underneath the smokebox door. Accommodating two 18 inch diameter inside cylinders resulted in some of the front cover fixing studs being shared between the valve chest front cover and the adjacent cylinder front cover, as shown in the picture below.
Preserved Caledonian Railway 439 Class No. 419: View showing cylinder front covers, divided by the front cover for the vertical valve chest.
Design evolution of the 0-4-4T on the Caledonian Railway
Preserved locomotive 419 is the sole survivor of the Caledonian Class '439' 0-4-4T, introduced by McIntosh in 1900 and the standard suburban and branch line locomotive throughout the Caledonian Railway. But its origins go back to Dugald Drummond who had learned the importance of simple, rugged design through his experiences keeping locomotives running on the harsh routes within Scotland. For general use, a four-coupled tank engine with a bogie at the back appealed to him and, in 1884, Drummond had introduced the '171' class of 0-4-4T. Following rebuild, the last of these survived until 1944. Dugald Drummond's influence on subsequent Scottish locomotive design should not be underestimated. His successor, Lambie, saw fit to continue the design with some changes as the '19' class of condensing 0-4-4T and, in turn, when McIntosh took over in 1895, production of 0-4-4T carried on, first with the '92' class condensing 0-4-4T and then, in 1900, with the '439' class (very similar to the '92' class with boiler pressure raised by 10 p.s.i. and slightly better water capacity). Each of these classes used 5 foot 9 inch diamter coupled wheels but McIntosh also produced 12 locomotives with 5 foot 6 inch diameter coupled wheels giving better performance on the more demanding Cathcart Circle (Glasgow) and Balerno branch (Edinburgh) lines. So successful was the '439' class that production (with minor changes) continued from 1915 under Pickersgill with the final batch of ten emerging in 1925, with the majority of the class remaining in service until the 1960s.
Preserved Caledonian Railway '439' Class No. 419: Overall view during preparation outside Shackerstone Shed.
Braking
The Caledonian Railway was one of a number of UK railways which opted to fit the Westinghouse Air Brake System as the 'automatic brake', rather than the vacuum brake system used by many UK railways. Locomotive 419 retains its working steam-operated reciprocating air pump (mounted outside the cab on the fireman's (right) side. The pump charges an air receiver fixed below the bunker of the fireman's side. Via the Driver's Brake Application Valve in the cab, brake blocks on the coupled wheels are applied or released by air applied to the air brake cylinder. Flexible air brake hoses at each end of the locomotive allow the locomotive to be connected to an air brake system on suitably-equipped vehicles. After the Railway Grouping, the LMS additionally fitted a vacuum ejector, brake application valve and standard vacuum brake hoses to enable vacuum-braked trains to be controlled but the power brake on the locomotive remained air-operated. There is also a conventional handbrake, operated by a screw at the rear of the cab.
Preserved Caledonian Railway 439 Class No. 419: Westinghouse Air Pump immediately outside cab on fireman's side.
Preserved Caledonian Railway 439 Class No. 419: Driver's air brake application valve fixed to cab sheeting, left side.
Preserved Caledonian Railway 439 Class No. 419: Davies & Metcalfe Vacuum Ejector and Brake Valve in front left corner of cab. Just to the right, the vertical black tube with a white top is the mechanical control for the blower valve in the smokebox.
Locomotive Regulator
'Double-beat' or 'balanced' locomotive regulators are employed to reduce the effort required to open and close a steam valve against high pressure steam. The Wikipedia article here explains the principle, invented by John Hornblower around 1800. The arrangement was subsequently adapted for use as a locomotive regulator valve. There are a couple of posts in this blog about locomotive regulators - Part 1 talks about early type of regulators and Part 2 shows a modern type of locomotive 'double-beat' regulator. Whereas unbalanced regulators usually have one (or sometimes two) long handles so that the driver can produce sufficient leverage to adjust the valve, this shouldn't be needed with a 'balanced' design. Locomotive 419 is fitted with a 'balanced' regulator, controlled by a short, dual, red-painted handle.
Preserved Caledonian Railway '439' Class No. 419: View of boiler backhead showing red-painted regulator handle and other driving controls from fireman's side.
Cab layout
Because of the dual vacuum/air braking, there's a satisfying array of Bourdon gauges on the front spectacle plate inside the cab. The whistle is operated by a round plunger extending through the front spectacle plate, which produces the satisfying sound of a "Caley Hooter". The deep-toned, dignified sound of the "Caley Hooter"is my favourite whistle. When Stanier moved from Swindon to the LMS, he was asked to agree the whistle to be used on his new designs. A series of whistles were set up on a 'whistle bar' for demonstration and he chose the "Caley Hooter" so, brought up in LMS/GWR West Midlands, I became accustomed to the slightly mournful sound of Stanier engines. Many of my friends prefer 'chime whistles' but I always thought them rather 'foreign' (since I was not exposed to Gresley 'Pacifics' until later!).
More features of the cab layout can be gleaned from the collection of pictures here.
Preserved Caledonian Railway '439' Class No. 419: Gauges mounted on spectacle plate, L-R Train Pipe Vacuum, Boiler P{ressure, Duplex Air Brake, Carriage Warming. The round, polished steel plunger below is the whistle valve.
John Farquharson McIntosh
McIntosh was responsible for many Caledonian Railway designs. He was apprenticed at Arbroath in 1860 and, completing his apprenticeship in 1867, was appointed to Montrose Works where he spent 10 years. Returning to work following the loss of his right hand in an accident, he became Inspector of Lines from Greenhill to Aberdeen. In 1882 he became District Locomotive Superintendent at Aberdeen, taking a similar role at Carstairs in 1884. Next, he took charge of Polmadie running shed in 1886, next becoming Chief Inspector of the Caledonian Railway Locomotive Department at St. Rollox works in 1891 under Lambie. On Lambie's death in 1895, McIntosh became Locomotive, Carriage and Wagon Superintendent of the Caledonian Railway until 1914.
John Farquharson McIntosh Locomotive, Carriage and Wagon Superintendent Caledonian Railway 1895 - 1914
Book References
[1] ‘The McIntosh Locomotives of the Caledonian Railway 1895-1914’ by A. B. Macleod (Ian Allan 1948).
[2] 'An Illustrated History of L.M.S. Locomotives: Volume Three Absorbed Pre-Group Classes, Northern Division’ by Bob Essery and David Jenkinson (Oxford Publishing Co 1986) ISBN 0 86093 383 0.
Related articles on other websites
At the time of publication of this post, the following links were valid but, regrettably, with the passage of time, they may become 'broken'. John F. McIntosh (Wikipedia)
John Farquharson McIntosh (Steamindex)
SRPS Collection Pages: 439 Class 419
No. 419 (55189)
Caledonian Railway 439 Class (Wikipedia)
There's a YouTube video of No. 419 at the Battlefield Line by Damien le Maistre Video here.
My pictures
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Preserved Caledonian Railway 439 Class No. 419
