Some notes on the GWR 64xx class
by Russ Elliott
6430 at Llangollen in April 2013. Photo permission of and copyright Polly Wilton.
Bachmann has made available 6406 in GWR green livery (with 'G W R' insignia), 6417 in BR unlined black livery with early emblem and 6412 in BR lined green livery with the late crest.
This small class of 40 passenger Pannier tanks was built in several lots: 6400–6409 in 1932; 6410–6424 in 1934/5; 6425–6429 in 1935; 6430–6439 in 1937.
At a total weight of 45½ tons, they were comfortably in the middle of the 'yellow' route category. All were autofitted, with screw reverse, and ATC. (In contrast to the 74xx class, which were lever reverse engines and not generally autofitted 1.)
For 6400–29, the front and rear of the cab roof had an overhanging lip, and the join between the cabside and the side of the bunker formed a curve. This is the body style portrayed by the Bachmann loco. For 6430–39, there was no overhanging lip on the cab roof, and the join between the cabside and the bunker side was a sharp right-angle. (Both these bodystyle variations seem to be covered by a single Swindon diagram, B62.) The body style of 6400–29 was inherited from the larger-wheeled 54xx class, the only significant superstructure differences on the 64xx being the smaller splashers and the buffers being at the top of the buffer beam. The 6430–39 body style was adopted on the 74xx class.
In common with other autofitted engines, the buffers of the 64xx class had packing pieces behind the buffer headstocks.
Footplate-mounted lubricators were fitted to 6400–09 when first built. For most of these locos, the lubricators were later repositioned, but at least 6400 and 6406 kept the lubricators in their original footplate position into BR days. Most of the rest of the class seem not to have been fitted with lubricators or had them positioned out of sight.
There were two different styles of front tank support – a solid front type, which extended to the smokebox, and an aperture type, which did not. The latter type was rare, but was fitted to 6406, 6407 and 6408, at least in their earlier years, and they may have migrated to some of the last batch of the 74xx class, 7442, 7444 and 7446 being so fitted with the aperture supports.
The style of the footsteps on the front of the tanks was a simple flanged one on 6400–09, but this changed from 6410 onward, these being welded ones having turned up sides.
Whistle shields started to appear in 1938. It is possible the whistle shield was initially of the small variety, but all locos were soon fitted with the large whistle shield, and 6430–39 may have been fitted with the large type from new.
For 6430–39, steps were fitted to the fireman's side of the bunker together with a grab iron between the cabside and the roof on that (left-hand) side, from new. These modifications were soon made to the earlier members of the class.
The number and position of the lamp stowage brackets on the left-hand side of the footplate varied – on some locos, they were adjacent to the front splasher, on other locos they were sited forward of the injector, and some locos appeared not to have any brackets at all.
Topfeed boilers began to be fitted from 1943 onward. However, the initial backhead-feed boilers continued in existence, and some topfeed locos could revert to non-topfeed on works' boiler swaps. Dated prototype pictures should be consulted.
The brake hangar bracket was of the same style on the 64xx and 54xx, but was different on the 74xx.
The electrical connectors on each bufferbeam (for the bell communication system between guard, driver and fireman) were fitted with a cover-box in late GWR days.
Although found on many parts of the system, up to 75% of the class were based in Wales.
The class went through all the expected livery variations: GREAT WESTERN (for 6400–6409 only), shirtbutton, G W R (both in green and wartime black), unlined black in BR(W) days (none are thought to have received BR(W) lined black), and several of the class received BR(W) lined green, including 6400, 6403, 6406, 6412, 6413, 6415, 6416, 6418, 6419, 6420, 6421, 6430, 6431 and 6437.
The class was fitted with cast-iron numberplates, although it is probable the numerals and perimeter of the plates were painted in a pale yellow-cream.
A Beginner's Guide to Pannier Tanks
Pannier Papers, No 7, 54XX, 64XX, 74XX, by Ian Sixsmith, Irwell Press, ISBN 978-1-906919-58-0
Build dates and shed allocations
1 Some 74xx engines were fitted with ATC for working the Fairford Branch. In addition to those listed there, 7403/4/23/27/45 were also fitted with ATC at some time.