Prototype history
Note the clear cab – no visible regulator and full backhead detail. Only needs a driver figure & fireman to complete the effect. They would also help to hide the poker burner. It would be good to have the driver leaning out of the cab with a rotating head linked to the reverser so that he looks in the direction of travel – no prizes for the first to do it! This one has the original Adams boiler and chimney, the picture at top shows the Drummond rebuild. The Chimney did not always match the boiler in later rebuilds.
The Adams Radial Tank (officially the 415 class, later O415 when put on the duplicate list) have a somewhat complex history. They were built by 4 different manufacturers –
Beyer Peacock – 12 built 1882, 1000 gallon tanks, 36″ trailing wheels, frame pattern 1
Stephenson – 18 built 1883, 1000 gallon tanks, 36″ trailing wheels, frame pattern 1
10 built 1885, 1200 gallon tanks, 42″ trailing wheels, frame pattern 1
Neilson – 11 built 1885, 1200 gallon tanks, 36″ trailing wheels, frame pattern 2
Dubs – 10 built 1884, 1200 gallon tanks, 36″ trailing wheels, frame pattern 1
10 built 1885, 1200 gallon tanks, 42″ trailing wheels, frame pattern 1, round spectacles
Frame patterns (front end) 1 small ogee at cylinder end, angled straight to buffer beam
2 large ogee at cylinder end, horizontal from final curve to buffer beam
some rebuilds as for 1, but simple curve instead of ogee
Note – all wheels have rectangular section spokes except for Dubs who used oval section spokes for bogie and trailing wheels.
Note that 488 as preserved has ended up with the incorrect oval spokes on the bogie wheels – this seems to have happened when the loco was restored for preservation. It also acquired strange wooden spectacle frames at this time.
All but 2 of these locos were withdrawn between 1921 and 1928. 125 and 520 were retained to work the Lyme Regis branch – other locos being too heavy. 488 had already been sold to the Government in 1917. In 1919 it went to the East Kent Railway.
SR bought 488 back in late 1947 and reboilered it with a Drummond boiler. As BR was formed on 01/01/48 it is possible (but not certain) that it never appeared in Southern colours. Correction – I have now found a picture of exactly that in 1949 – see page 184 of Barry Curl’s book.
Drummond hated stove-pipe chimneys (and often seemed to move to Railways using them!) so he replaced the Adams chimneys with his own design. He also replaced some of the boilers with ones where the safety valve was moved to the top of the dome.
Some locos were fitted with double slide bars and crossheads in place of the Adams single bar design.
He also fitted coal rails to the bunker and some engines had motor train gear on the cab roof.
The result of all this is that there is no real substitute for photos of the loco you are modelling!
MODEL DESCRIPTION
This model is to ACCURATE 1:32 scale – height 113.8mm, width 81mm. No compromises have been made to achieve this, just intelligent design to compensate for the smaller boiler needed to fit the scale cladding. The dome is functional allowing the boiler to be completely filled (as opposed to say 80% full in an ARM1G boiler – even with the smaller boiler diameter this gives 120% of ARM1G capacity and a projected run time of 54 minutes between refills) – this is fine for the Drummond version with the safety valve on top of the dome, but would cause problems with the lower safety valves on the Adams version. This problem is overcome by feeding the Adams safety valve remotely from the dome. The gas tank is unfortunately smaller than the ARM1G but should still be sufficient for a 33 minute run. The use of Stephenson’s reversible valvegear instead of slip eccentric should improve efficiency and runtimes further. The smaller gas tank is caused by having to fit the displacement lubricator transversely across the back of the bunker. I initially designed it into a side tank then realised that the loco has no fillers on the top of the side tanks requiring a change of position so the lubricator could be emptied and refilled.
The loco will be available in both Adams and Drummond versions with any combination of bits (the boilers got swapped around a lot) with early short side tanks or later long ones, original or modified cab, rectangular or round spectacles, with or without coal rails and different frames. They changed so much over their lifetimes there is probably some combination I have missed. Initially only the rectangular spoke section wheels will be available, but I may do the oval section ones (Dubs built locos) if there is sufficient demand.
Like all of my current models this is entirely made of nickel silver with lost-wax brass castings made from 3D printed masters, copper boiler, thick walled brass gas tank and, in this case, cast-iron wheels. The boiler uses a single flue with a poker burner that is remotely adjustable for idling.
The model is radio controlled only – no manual option – it would have involved too many compromises.
See here for more details of the R/C system. It provides controls for the regulator, reverser, idling the burner and uncoupling. It also provides feedback on speed, boiler pressure, water level and battery voltage with warnings when pressure goes too high, or voltage or water level too low. The system is fully integrated at no extra cost.
References
Wikipedia https://en.wikipedia.org/wiki/LSWR_415_class
Maskelyne J. M. Locomotives I have known MAP Out of Print
Roche F. J. Historic Loco Drawings in 4mm scale Ian Allan Out of Print
Curl B. The LSWR at Nine Elms Kestrel
Burtt F. LSWR Locomotives Ian Allan Out of Print
Russell J. H. A Pictorial Record of Southern Locomotives OPC Out of Print
Herring P. Handbook of Classic British Steam Locomotives Island Books ?
Harris M. Locos Illustrated 59 Ian Allan Out of Print
LSWR Outside Cylinder Tank Locomotives
NRM Works GA drawings
Preserved loco (488) at the Bluebell Railway
http://www.bluebell-railway.co.uk/bluebell/pics/adams_tank.html
Downloads
Click here to download the illustrated instructions
Click here to download the punching rivets PDF from Google Drive and other common PDF documents
This is currently a work in progress – most of the exploded diagrams are present, but most need the words added. It will at least give you an idea of what is involved.