Background – A Replica ‘Crampton’ Locomotive Design Specification
The Crampton Locomotive Trust wish to create a working replica of locomotive No 81 , the first of three designed by Thomas Crampton for the South Eastern Railway and built by the Whitehaven firm of Tulk & Ley in 1847 as works No 13.

The system patented by Thomas Crampton was enthusiatically adopted by railway companies in France and Germany, and the locomotives subsequently built brought a revolution in express train services in those countries. Unfortunately no British examples survives despite the fact that significant numbers were used by the South Eastern and the London, Chatham and Dover railways. The Trust intends to fill this gap in British railway history.

Philosophy
The new locomotive will be as near to the original design as possible and will be constructed using identical techniques. Some changes to ensure safety in operation may be required but these will be engineered to have as little impact on visual appearance as possible. Materials will be as originally specified except that steel will largely replace wrought iron as that material is no longer available new.

Reference Material
No original design drawings are known to survive. It is likely that they were all destroyed in the fire at the Lowca Works in 1912.
Some outline drawings exist, however in most cases the origin of the drawings are unknown and they are sometimes contradictory.
The only known relevant publications are ‘The Crampton Locomotive’ by Mike Sharman 1983 and ‘Die Crampton-Lokomotive’ by F. Gaiser 1909. Both are out of print but secondhand copies are available.
The first two locomotives to be built to Crampton’s design were made by Tulk & Ley in 1846 and the same firm built 6 more between 1846 and 1854. A further 35 were built by various other British builders between 1846 and 1862. French and German manufacturers built several hundred for use in those countries between 1849 and 1863.
Only one locomotive survives, ‘Le Continent’ of 1852 which is preserved in France. There is also a 1920s replica of ‘Die Pfalz’ in Germany.

There were considerable differences between the various locomotives and information about non Tulk & Ley built locomotives is therefore of limited use for the task of building the replica. The German replica has however been examined and it does exhibit at least a family resemblence to the Tulk and Ley locomotives. The differences between the French and German locomotives and SER No 81 are summarised in Table 1.

Sharman lists the key dimensions of the locomotives and these indicate that Tulk & Ley work nos 10, 11 , 13, 14, 15 and 16 were the same. (Gaiser lists different firebox size, heating surface and tube length for nos 13, 15 and 16 however it has been assumed this is an error)

The locomotives that are of interest are therefore:
Railway Works No Date Name/No
Belgian 10 1846 Namur
Belgian 11 1846 Liege
Dundee P & A 14 1847 Kinnaird
South Eastern 13 1847 81
South Eastern 15 1847 83
South Eastern 16 1847 85

The differences in the other Tulk & Ley locomotives are:
‘Courier’
‘London’
larger pony wheels, slightly different wheelbase, a smaller almost round boiler and valve chests on top of the cylinders.
larger driving wheels, longer wheelbase, larger boiler diameter, larger cylinders, longer tubes, longer grate and side springs for the rear axle.
‘M&C no 12’ larger leading pony wheels, longer wheelbase and a smaller round boiler

The most relevant sources of information are all from Sharman and can be summarised as
follows:
Plate 5
Fig 6
Figs 20/21 /23
Figs 30/31
Fig 34
Fig 35
only known photo of a Tulk & Ley Crampton showing Dundee, Perth and Aberdeen Junction railway locomotive ‘Kinnaird ‘ layout of the boiler and in particular how the grate is considerably larger than the upper part of the firebox.

construction of boiler and in particular the method for staying the oval
shape, albeit for the larger boiler fitted to the locomotive ‘London’
side and end views of SER no 81
side and end views of the tender for Maryport and Carlisle locomotive
no 12, said to be the same as for SER no 81 :
layout for the cylinders and valve gear for Maryport and Carlisle
locomotive no 12. The cylinder layout, diameter and stroke are the
same as for SER locomotive no 81.

The Design in Detail
Section 1, The Locomotive
1.1 Frames
The side plates are from 25mm MS, water jet profile cut complete with positioning holes. Stretchers & headstock support plates are from 12mm plate. The ends of the side frames are flanged out to form the riveted connection to the buffer beam support plates at the leading end & the tender draw plate at the trailing end. The stretchers are attached to the side plates by riveted double angles.
The carrying wheel horns are of cast iron riveted to the side plates, the hornstays comprise continuous bars of MS linking the the two carrying wheels with the leading rail guards, these are fixed by bolts.
At the leading end of the frames seasoned oak buffer beams are bolted to the support plates.
The inverted driving horns are fitted with U shaped hornblocks with fitted hornstays, the horns are riveted to the side frames.
The cylinder block is fitted to the side frame using fitted bolts attched to an upward extension of the frame.
1.2 Buffing & Draw Gear
At the leading end certified chains and hooks are fitted as per the prototype. These can be adapted to connect with standard 3 link couplings if required . The buffers are externaly as per the prototype, clad in leather with iron hoops, internaly the original horse hair stuffing is replaced by a spring. At the trailing end there is a double cross frame drag beam mounted inboard fitted with a coupling pin to receive the tender drawbar. Safety chains are provided between tender and locomotive.
1.3 Wheel Bearings
The carrying axleboxes are of cast iron fitted with bronze slippers to the horns. Bronze liners are fitted and the cast iron keeps are fitted with “Armstrong” oiling pads and fitted to the axlebox by S/S pins. Lubrication is by wick feed oilers fitted inside the frames. The upper part has a hole to receive the spring pin.
The driving axleboxes of the inverted type are of alloy cast iron with bronze liners fitted to both the upper & lower parts & bronze slippers to the horns. The lower parts are fitted with “Armstrong” oiling pads. Lubrication is by wick feed oilers fitted inside the spashers. The upper part has a buckle to receive the spring pivot.
1.4 Driving Wheelset
The driving axle is of forged alloy steel with 6-1/4″ Dia Journals 9″ long subject to final arrangement. Wheel seat nom 6″ long. Crank pin press fit & weld inside.
At the time of the prototype the wheel centres would have been built up in wrought iron.
The method for this was to forge the individual spokes complete with a section of “felloe” or rim section on one end and a wedge shaped segment of hub on the other end. When all the spokes had been made they were offered up to form the assembled centre and then firewelded in the forge to join the felloes to form the rim. The hub was then formed by firewelding a thick washer to either side of the assembled hub wedges. The whole assembly was then turned & bored to receive the axle and tyre. Unfortunately it is not possible to replicate this method now, recycled wrought iron is available, but the skills to achieve this reliably have long gone.
To replicate the wheel centre as a casting , and still retain the detail and elegance would be very difficult, so it is proposed as follows-
Create each spoke as a seperate casting or forging in alloy steel, complete with rim & hub
section, suitable machining allowance & weld prep.
Assemble in a jig to form complete centre.
Tack weld the assembly.
Fully weld using the appropriate welding proceedure and NOT checks.
There are variations possible on this method to allow creation of the crankpin boss.
Machine to press fit to axle and receive shrunk on tyre.
In addition to the shrink fit the tyre is secured by rivets as per the prototype.
The tyre is of ring rolled alloy steel.
1.5 Carrying Wheelsets
Axles of forged alloy steel with 5″ Dia Journals 9″ long subject to final arrangement. Wheel seat nom 6″ long.
Wheel centres cast steel. Note the slender proportions of the wheel centre may require a fabricated method as per the driving wheels, to be investigated.
In addition to the shrink fit the tyre is secured by rivets as per the prototype.
The tyre is of ring rolled alloy steel.
1.6 Springing
The carrying wheelset springs are leaf springs mounted inside the frames. Detail design to be carried out when the weight distribution for the loco is known.
The driving wheelset springing is by transverse leaf spring bearing on the axleboxes, the proportion of the weight of the loco being carried on a cast steel bracket riveted to the boiler backhead.
1.7 Cylinder Detail
The cylinder blocks are of cast iron, the casting incorporates both the valve & regulator chest. The valve port face is vertical facing out & the regulator is horizontal over the top. A tail rod support is provided for the valve.
The pistons & rings are of Cast Iron & the rod Stainless Steel. Slide valve Bronze. The piston rod is tapered at both ends also screwed and nutted at the -piston end with a cotter to fix to the cross head.
Bronze stuffing glands are provided & are packed with PTFE packing. Bronze neck rings are fitted to guide the piston & valve rods.
Steam oil is supplied via an oiler mounted on the regulator chest cover, and also by a mechanical lubricator driven off the valve gear. (Not shown on sketches)
Cylinder drains are provided, linked back to the footplate. (Not shown on sketches)

1.8 Motion Work
The slide bars are of alloy steel & are supported off the valve chest & motion bracket. The motion bracket is built up from plate & angle & is riveted to the frame. The motion bracket also supports the feed pump & the guide bush for the valve rod.
The crosshead is of cast iron with bronze slippers & incorporates the bracket for the pump rod drive.
The connecting rod is of alloy steel fitted with split brasses at both ends, the big end having a strap, gib & cottter & wick feed oiler.
1.9 Valve Gear
The valve gear is Stephensons with open rods driven off the return crank. The return crank is pressed & keyed onto the crankpin. The eccentric pulleys are cast iron, pressed & keyed onto the return crankpin , the straps alloy steel with bronze liners & wick feed oilers. The eccentric rods are integral with one half of the strap and have bronze bushes fitted at the expansion link. The weighshaft is mild steel with cast iron bearing blocks fitted with bronze liners.
The lifting links, expansion slot, bell cranks & reach rod are all in alloy steel & all pins are bushed with bronze & the pins heat treated after final testing of the valve gear. Die block bronze.
The reversing lever is in mild steel & incorporates provision for expansive working .
1.10 Fee~ Pumps
The body, piston & rings are cast iron, inlet & delivery valves in bronze. A pressure relief valve is fitted to protect the casting , the pumps can be isolated from the boiler for maintenance. Pump rods of S/S with bronze stuffing glands.
Pumps are fitted to both sides of the Locomotive.
1.11 Sanding Gear
The sand boxes are of cast iron, with a cast iron filler lid . The valve rod & valve are fitted with a sealing gland. The boxes are fixed to the running board and the spashers.
Pull rods in mild steel with support brackets off the splashers.
1.12 Pipework
Pump feed pipe copper, with flexible rubber coupling to tender. Sand pipes copper.
Exhaust pipes to smokebox & live steam from dome S/S steel
1.13 Footplating, Splashers, Steps & Handrails
The running board is seasoned oak, supported off the buffer beam by a turned pedistai & various brackets including the motion bracket. Footplates are mild steel & there is a cover to protect the driving axle. The splashers are of mild steel, profile cut, there is an attached section to cover the driving crank path. The splashers are braced off the footplate, boiler & running board. Forged steel steps are fitted to the trailing beam. Curved steel handrails &  support brackets are fitted to the top of the splashers, also to the boiler with turned pedistals
1.20 Boiler
Many early Crampton locomotives, including SER no 81, had oval boilers. The boiler was taller than it was wide presumably to allow it to fit between the large single driving wheels.
Figs 20, 21 and 23 show the boiler fitted to the 1848 built locomotive ‘London’. This was both 5″ wider and taller than that fitted to SER no 81. It is likely however that the construction was similar.
The barrel is formed of semi circular upper and lower sections joined at both sides by a flat plate. The joints appear to be single riveted. There are 22 transverse stays to hold the flat plates together and 7 longitudinal stays.
The firebox crown is supported by five T Iron girder stays. It is not known whether the inner firebox was copper or steel.
Working pressure for SER no 81 is given by Sharman as 90psi (p10) or 50psi (p18).
Gaiser gives 90psi.
The boiler fitted to the German replica ‘Die Pfalz’ has been examined but its locomotive survives, ‘Le Contwn. The outside is covered by cladding and there is no internal access. The following has however been established:

Boiler barrel is oval. It is approximately 2″ taller than it is wide (Gaiser gives 60mm).
This is not as great a difference as for SER no 81 but more like the 1847 built ‘Courier’.
Inner firebox is copper with steel lap seam rivets.
Outer firebox is of flat plate construction with corner angle irons.
Firebox side stays are approximately 4″x 4″ pitch.
The crown stay nuts are 4%” x 4%” pitch but it is not known whether direct stays or girders are used.
No fusible plug is fitted .
Waterway width at foundation ring level at the backhead is 3″
Six longitudinal stays of approximately 1 1 /8″diameter are fitted at 4 %” pitch.
Steel boiler tubes are fitted , beaded at firebox end , 1 7/8 internal diameter at the
smokebox end.
Smokebox tubeplate is the ‘set on’ type, attached to an angle ring on the boiler barrel.
Boiler is attached to the front of the locomotive frames via the smokebox. There are also plates attaching both the boiler barrel and the front of the firebox to the frames.
A maximum working pressure of 95psi (6.6bar) is indicated by a red line on the pressure gauge. (Gaiser gives 6.3bar or 91 psi)

It is proposed that the boiler for the replica of SER no 81 will be as follows:

All riveted construction.
Outer shell of steel, inner firebox of copper (unless research suggests otherwise).
Oval boiler barrel, 51 ” tall x 41 ” wide as per Sharman p10.
Boiler barrel horizontal lap seams to be double riveted as single riveted is unlikely to provide a satisfactory joint efficiency.
Cross and longitudinal stays generally as per Sharman figs 20/21/23
Firebox shape as per Sharman figs 20/21/23
182 steel boiler tubes, 2″ OD x 1 OSWG

1.21 Safety Valves
Two salter type valves mounted on the steam dome as per Sharman figs 30 and 31 .
1.22 Boiler Fittings
Water level gauge one off, as per Sharman fig 31
Water try cocks two or possibly three off.
Pressure gauge discreet. (the bourdofrom 12mm plate. The ends of theexistence a few
years after the locomotive was built. It would not have had one initially
but one may have been fitted later).
Water pump crosshead driven, one each side
Injector one off, hidden. (the injector was not invented for another 10 years so the locomotive would not have had one originally)
Whistle as per Sharman fig 31
Blower Possibly not required and probably not fitted originally (German replica ‘Die Pfalz’ does not have one). Consideration will, be given to the need to incorporate one discretely.
Slowdown Valve Fitted to rear of firebox as per Sharman Fig 31

1.23 Boiler mountings
Unknown at present but need to allow for the vertical forces as a result of the rear axle spring being attached to the boiler backplate.
1.24 Smokebox, Smokebox Door and Chimney
As per Sharman figs 30 and 31 .
1.25 Ashpan and Dampers
As per Sharman figs 30 and 31
1.26 Cladding and Handrails
As per Sharman figs 30 and 31 and photograph of ‘Kinnaird’ (Sharman Plate 5)
Section 2, The Tender
2.1 Frames
The side plates are from 25mm MS, water jet profile cut complete with positioning holes. Stretchers & headstock support plates are from 12mm plate. The ends of the side frames are flanged out to form the riveted connection to the buffer beam support plates at the leading end & the tender draw plate at the trailing end . The stretchers are attached to the side plates by riveted double angles.
The carrying wheel horns are of cast iron riveted to the side plates, the hornstays comprise continuous bars of MS linking the the two carrying wheels with the leading rail guards, these are fixed by bolts.
At the trailing end of the frames seasoned oak buffer beams are bolted to the support plates.
The spring hanger brackets of alloy steel are riveted to the side plates, sundry brackets are bolted in place.
2.2 Buffing & Draw Gear
At the trailing end certified chains and hooks are fitted as per the prototype. These can be adapted to connect with standard 3 link couplings if required. The buffers are externaly as per the prototype, clad in leather with iron hoops, internaly the ori§inal horse hair stuffing is replaced by a spring. At the leading end there is a double cross frame stay mounted inboard fitted with a coupling pin to receive the loco drawbar. Safety chains are provided between tender and locomotive. Full length tie bars are fitted to connect the trailing buffer beam to the inboard drag beam at the leading end to transfer the drawbar load through the tender.

2.3 Wheel Bearings
The axleboxes are of cast iron fitted.with bronze slippers to the horns. Bronze liners are fitted and the cast iron keeps are fitted with “Armstrong” oiling pads and fitted to the axlebox by SIS pins. Lubrication is by wick feed oilers fitted inside the frames. The upper part has a hole to receive the spring pin.
2.4 Wheelsets
Axles of forged alloy steel with 5″ Dia Journals 9″ long subject to final arrangement. Wheel seat nom 6″ long.
Wheel centres cast steel. Note the slender proportions of the wheel centre as shown on the line drawing may require a fabricated method as per the loco driving wheels, to be investigated. Photo of “Kinnnaird ” shows a cast wheel.
In addition to the shrink fit the tyre is secured by rivets as per the prototype.
The tyre is of ring rolled alloy steel.
2.5 Platework
The tender floor is of steel plate 8mm thick, fixed to the frame by countersunk screws. The water tank is a riveted assembly in 4mm plate, complete with floor plate, comprising plates and angles. The corners of the tank are radiused. The plate joints are sealed during assembly and the plate edges caulked up on final assembly. Baffle plates are fitted, also acting as supports to the platework. The splayed out top edge is trimmed with beading.
A cast irdn filler lid is provided.
2.6 Springing
The wheelset springs are leaf springs mounted outside the frames. Detail design to be carried out when the weight of the tender in working order is known.
2.7 Pipework
The tank is fitted with two water valves for left & RHS pumps & injector supply. Steel pipework takes the water to the leading beam, then via the flexible rubber pipe to the loco.
There is a drain valve to the tank.
2.8 Handbrake
The handbrake operates on all wheels, wood blocks are fitted . There is a cast column & handle on the fireman’s side (left hand side)
2.9 Train Brakes
The tender & loco are piped for two line air control , with air couplings leading & trailing, with flexible couplings between tender and loco. The driver’s brake valve is mounted on the loco. The tender is air braked & there is an option to fit an on board air supply to the  tender.

Design Specification Drawings – click here

Graham Morris & David Potter
28/03/13