By Doug Hewson

I just wanted to introduce you to the new LNER B1 drawings which I am preparing for publication. They are not available yet I am afraid, but will be either later in the year or early 2021.

(Ed’s note: This revised drawing replaces one published on MEWS earlier. Please replace any earlier download with this version.)

This should be a replacement for the design which Martin Evans drew in 1955. When Martin drew his B1 there were not the same facilities available to us model engineers, such as laser cutting and lost wax casting and, furthermore, the drawings were not available for us to produce the detailed models that we can today. Nowadays there is no excuse for not producing models which are highly detailed.

Beginning with the tenders I have drawn all five different tenders which the B1s were paired with. Fortunately, all of the 410 B1s built kept their own tenders for their whole lives making things a whole lot easier, for me at least. 

The first ten tenders had low coal plates, both front and rear of the bunker, but they were all altered during the 1950s to make them nearer to the cab profile. The remaining tenders were all the so called ‘Group Standard’ type but they are far from Standard in real life. 

The water valve for the injectors were the main differences as Doncaster built locos all had the vertical water valves but the Darlington ones had them inclined outwards by at about by 10½°.  Details of all the locos which had the inclined ones are all on the drawings. 

Also, the tenders built at Darlington had a plate riveted along the top of the sides, some with flush rivets on the outside and some tenders had snap head rivets along the inside. The locos which had these tenders were 61352 to 4 and 61357 and 61355 & 6 and 61400 to 61409 had all countersunk rivets both sides.  The tenders on locos 61400 – 09 had their drag beams cropped off at the bottom to meet the frame plates.

The remaining B1s all had flush sided tenders top to bottom. I have not included the ten self-weighing which were swapped around various locos throughout there lives.

Beginning with the frames, I have designed them for the two different locos as the frame plates were changed at 61340 onwards, with the back ends being squared off and the same with the fronts of their respective tender frames which were made to match. I have drawn both types and there are notes on the drawings to suit which had which.

There were three different types of driving and coupled wheels. The first ten B1s were all built with V2 driving and coupled wheels and from then onwards the B1s got their own wheels with the balance weights 183° in retard of the crank pin. However, the driving wheels all had additional plates riveted on their faces and were positioned 185-15°min in retard of the crank pin. See my Drg No4 for details of all the wheels.  The ones on 1306 and 61264 show the difference in the two wheels, fortunately for us modellers who like to get things right!

There are two different front bogies, one has leaf springs and the other has coil springs. However, it looks to me as though (from looking under the engine) 61264 has both types of springing so I have copied the leaf spring one from the works drawings as that was the only one I could find in the NRM. There are also five different front stretchers on the front bogies so I have given all their details and all the different loco numbers as to which has which type are on the drawing No4.

The valve gear has all come from Don Ashton who very kindly sent me all the full-size dimensions which I needed to construct the valve gear drawing.

On the full-size drawings of the cylinders they are obviously blind bored from the front which makes it very difficult for model engineers to replicate so I have added at thin rear cover made in mild steel so that the slide bar brackets can be easily silver soldered on to it.

I have designed a proper new 100A LNER boiler for the engine but the drawing for this is not finished at the time of writing.  This will have all of the prototype controls for the engine but I am just trying to fathom out the correct ‘SJ’ vacuum brake ejector for this engine.  I do have the BR Black Book, but it is not in there! 

There is adequate lagging on the boiler. The correct schematic diagram of the SJ ejector has been passed on to me by a friend.

I have almost finished the smokebox drawing (see below) and I have detailed all four different types of doors which the B1s were built with. There were at least two which were the same diameter, but they were different radii.

The locos 8301 to 8310 all had smaller doors which were quite a large radius but note that the handrails over the doors followed the radius of the door and then had extra kinks in either side to align with the handrails along the boiler. This did not apply to any of the other B1s.  On these doors the hinges were at 2 1/8” centres. On locos Nos 8311 to 61349 the doors changed to 5 1/16” diameter and were about 1” smaller radius but the main thing was that the door hinges were set only 1 5/16” apart so the BR loco number plate had to be placed above the top hinge rather than below it.

From 61350 onwards the doors were the same diameter but the radius was changed to a very much smaller radius of 6 7/8” which seemed to make it a much bulkier door, but the hinges were now back to the 2 1/8” apart so the smokebox No plate was back in the more conventional position of below the top hinge.

Most of the B1s which were overhauled at St Rollox works had some little fillets added beneath their platforms so when I get round to detailing those I will be adding those to the alternatives.

Provisionally the drawing list so far is as follows.

Drg 61000_01 (above) is the GA which shows the two different sets of frame plates.

Drg 61000_02 is the frame plan and elevation (unfinished as yet as I keep adding to it!).  It also has the axle boxes, axles and suspension. 

Drg 61000_03 is the frame stretchers with the everlasting blowdown, screw coupling and two different drawbars on it, one for sharp radius curves and one for larger radius curves.

Drg 61000_04 is the 6 different driving and coupled wheels on it, the front bogie with all five different front stretchers and all the side control gear.

Drg 61000_05 is all the brake gear and the cross sections of the engine including one showing the position of the everlasting blowdown valve

Drg 61000_06 is all of the valve gear including the arrangement of the valve gear.

Drg 61000_07 is the cylinder drawing, the lubricators, various swab boxes, reverser and cylinder drain cock gear (not quite completed yet)

Drg 61000_08 (below) is the smoke box drawing with all the smokebox doors, superheaters, Snifting valve, smoke box in the flat showing all the dimensions needed for setting it out, smokebox door ring darts and keys.

Drg 61000_09 will be the ash pan and rocking fire grate with a more simple one alongside.

Drg 61000_10 is the 100A Boiler with lots of fittings including the fire hole door and regulator.  (not completed yet)

Drg 61000_11 This is intended to be the cab details and the side platform and steps etc.

Drg 61000_12 This is intended to be the GA of the right hand side of the engine.

Drg LNER GST 001 is the LNER Group Standard tender GA showing some of the differences between the tenders.

Drg LNER GST 002 is the general arrangement of the tender tank

Drg LNER GST 003 is the general arrangement of the underframe

Drg LNER GST 004 not finished yet

Drg LNER GST 005 shows the water scoop gear, brake gear and lots of details of such things as the wheels, axles, suspension, brake cross shaft, screw coupling, tender buffers, draw hooks and intermediate buffers.

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