One of the largest engines built by Fowler, the Z7 was originally developed for overseas markets, where the type of ploughing undertaken in sugar plantations required a more powerful engine than hitherto produced. The Z7 appeared in the early years of the twentieth century, followed shortly thereafter by the superheated Z7S derivative, rated at 275ihp.
Starting from John Haining's excellent "Superba" design serialised in "Model Engineer" from 1988, the builder made several modifications to make the model closer to prototype, notably designing and casting a piston valve cylinder block. In a practical departure from full-size practice, a brake has been discretely fitted, operated by a wheel installed in the tender.
Built to a high standard throughout, the engine has been carefully used and well maintained throughout its life. The boiler, by Cheddar, has had recent test and remains in excellent condition. The Fowler smokebox superheaters - never a great success in the original engine - have been replaced in the model with four radiant superheaters which look capable of producing some highly energetic steam.
Paintwork is plainly finished, as per the prototype. The engine runs very well - there's a clip here of it ticking over outside the workshop following boiler test this morning.
Complete with drawings, along with builder's notes and blanking plates for testing the boiler.
length/inches | 51 |
width/inches | 19 |
height/inches | 28 |
weight/kg | 151 |
cylinder material | cast iron |
valve type | piston |
valve gear | Firth radial |
reverser type | pole |
lubricator type | mechanical |
injector(s) | 1 |
boiler number | CM0291 |
year built | 1994 |
boiler maker | Cheddar Boilers |
CE mark | n/a - pre-2002 |
working pressure/psi | 100 |
boiler type | locomotive |
boiler material | copper |
boiler construction | silver soldered |
hydraulic test valid to | 1-Apr-23 |
steam test valid to | 2-Jun-20 |
superheater(s) | 4 |
superheater type | radiant |
safety valve(s) | 2 |
safety valve type | Salter |
mechanical pump | 1 |