Lady of the Lake (Ramsbottom version)
I was commissioned to make two Ladies of the Lake (Lady of the Lakes?), one in the original condition as built by Ramsbottom between 1859 and 1865, and one rebuilt by Webb in about 1896. This is the as-built loco.
There are few photos of the class as built, but the LNWR Society has published a drawing that appears to be quite accurate, and there is also a large-scale model built by someone who worked for the LNWR and can be assumed to know them, in Rugby museum. I visited and took lots of photographs.
There are many photos of the rebuilt engines, and a drawing in J. N. Maskelyne's book Locomotives I Have Known, which again appears to be quite accurate.
My client was keen that I should use a tender drive so as to leave space for the inside valve gear, so I ordered one from ABC Gears. It is basically the bogie unit that Brian Clapperton makes for diesel and electric locos. There are pros and cons to this approach. It certainly makes construction of the valve gear easier, but it does mean that the driving wheels must be very free running. That problem was solved, not by adding lots of modeller's slop, but by making the components scrupulously to the drawing, and paying close attention to assembly and alignments. On the whole I prefer the more conventional approach of powering the loco, and I did that for the model of the rebuild.
The main problem of construction is having the smokebox and cylinders in a common wrapper. That assembly stays attached to the frames. The cylinder front, slidebars, motion plate, crosshead, etc, is a separate assembly that pushes into the cylinder body, and the boiler and firebox assembly bayonets to the back of the smokebox.
There are few photos of the class as built, but the LNWR Society has published a drawing that appears to be quite accurate, and there is also a large-scale model built by someone who worked for the LNWR and can be assumed to know them, in Rugby museum. I visited and took lots of photographs.
There are many photos of the rebuilt engines, and a drawing in J. N. Maskelyne's book Locomotives I Have Known, which again appears to be quite accurate.
My client was keen that I should use a tender drive so as to leave space for the inside valve gear, so I ordered one from ABC Gears. It is basically the bogie unit that Brian Clapperton makes for diesel and electric locos. There are pros and cons to this approach. It certainly makes construction of the valve gear easier, but it does mean that the driving wheels must be very free running. That problem was solved, not by adding lots of modeller's slop, but by making the components scrupulously to the drawing, and paying close attention to assembly and alignments. On the whole I prefer the more conventional approach of powering the loco, and I did that for the model of the rebuild.
The main problem of construction is having the smokebox and cylinders in a common wrapper. That assembly stays attached to the frames. The cylinder front, slidebars, motion plate, crosshead, etc, is a separate assembly that pushes into the cylinder body, and the boiler and firebox assembly bayonets to the back of the smokebox.
The next big assembly was the boiler and firebox, which I made in my usual way by rolling 0.25 mm nickel silver wrappers and fitting them around a skeleton frame. The boiler turned out well, but the firebox needed a U-shaped wrapper, and that came out of the rolling bars slightly, but noticeably, saddle-shaped. I don’t recall that ever happening before, and the only reason for it that I can think of is that the pressure on the rolling bars was excessive, so that the rollers bent slightly, putting more pressure on the edges of the plate than in the middle, causing the edges to stretch and take up a larger radius than the centre.
My rollers are 12mm diameter. They could be a bit bigger (and more rigid) and still roll this boiler, but I was not about to make a new set of rolling bars just for that. So a lot of filing and fitting ensued. It is still not quite right, but it is acceptable. Next time I will be more careful not to use more pressure than necessary to see if that solves the problem.
My rollers are 12mm diameter. They could be a bit bigger (and more rigid) and still roll this boiler, but I was not about to make a new set of rolling bars just for that. So a lot of filing and fitting ensued. It is still not quite right, but it is acceptable. Next time I will be more careful not to use more pressure than necessary to see if that solves the problem.
Here is the backhead, the reverser and one of the ejectors. The ejectors are slightly simplified because when the sidesheets are in place they are mostly hidden. The backplate is very sparse compared with more modern engines. I subsequently learned that on the prototype, the reverser was mounted on the side of the firebox rather than on a separate plate. That was not apparent on the drawing. At least it doesn't show, and does make disassembly easier. (It must have been a nuisance on the prototype too).
Lady of the Lake - Ramsbottom version
Ian Rathbone did his usual superb job of the painting and lining.
Just for fun, I made the reverser work. By turning the handle, it goes from full forward to full reverse gear.
After that it was the boiler bands. On previous models I have used copper shim for this. It is 0.08mm thick which is pretty much scale thickness. I used to cut it with a knife into strips of the right width and solder it in place. But it is very soft and difficult to work with. So this time I tried 0.12 mm shim brass. First I soldered it to a thicker piece of brass to saw it, but then discovered I could cut it by itself if I angled the piercing saw blade right down near the surface so several teeth were in contact with the metal at the same time. With careful cutting and a bit of filing afterwards, the strips were quite acceptable. Probably a bit thicker than scale, but the overall effect is good.
Nick Baines • Model Engineering
FORWARD
REVERSE