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| GWRdriver:
I've had someone suggest that I start a project blog to describe what I've been up to lately . . . so what follows will be an account of my current project, a 7.5" gauge version of LBSC's TICH, a British 0-4-0 contractor's locomotive. The TICH was originally designed by LBSC as a beginner's locomotive in 3.5" gauge and has since become the world's most popular live steam locomotive in numbers of castings sold and in running locos built. If you don't know who LBSC was you can look here http://en.wikipedia.org/wiki/Curly_Lawrence for a thumbnail biography of this prolific but eccentric and often controversial model locomotive designer. While the TICH would run very well with a good fire it had a small boiler and firebox and proved to be very difficult to fire on the run or by the inexperienced and was typically capable of pulling only a couple of adults. Nevertheless thousands were built over the years and it provided an excellent entry-level training project for aspiring live steamers. The construction articles were serialized in The Model Engineer magazine beginning in Vol.100 (Jan 1949) and subsequently appeared in book form as "The Live Steam Book." Since the TICH had no specific prototype it was often the object of personal interpretation in detail and finish, as mine will be. The 7.25"/7.5" gauge version was developed in the 1960s by Charles Kennion of Chas. Kennion & Son (Herts, UK) when it was found that the 3.5" gauge TICH design simply doubled, with a few adjustments here and there to accomodate scaling, produced a good running design. Until their closure Kennions provided castings and drawings for the 2X version and these continue to be available from GLR Distributors (UK), who acquired the Kennions designs. Since that time experiment has shown that a few modifications, such as an increase in cylinder bore from 1.375" to 1.50" or even 1.625", produces a more powerful and better running locomotive. Another significant influence on my project is the work of Kennedy (Ken) Swan, of Co.Durham UK. Ken is an engineer and model locomotive designer whose very successful and popular design for the 0-4-2 BRIDGET locomotive was drawn upon frequently for guidance or inspiration, and a few parts. The single bought out item (so far) in my TICH are the 5" diameter drivers which were for the BRIDGET. My TICH project was originally conceived as a simple build-one-as-fast-as-you-can club locomotive, but almost immediately I began to change things which I felt would improve the design by making for longer life, easier repair, more power, etc, and in the process I discovered that I can't build one fast - Life always seems to get in the way. I estimate that the project is now about 70% done and to date I have about 1250 hours of hands-on construction time and between 700 and 750 hours of design and drawing work in the project. That may seem like a lot of drawing time, and it is, but I changed my mind often about how to do things or how things should look. I haven't kept track of my research, thinking, scavenging, material search, etc, time - hundreds of hours probably, and I expect to eventually have between 1800 and 2000 hours construction time in the completed locomotive. So here we go and I'll post photos and descriptions as time permits. |
| Brass_Machine:
Very cool. Anxious to see what you do. Eric |
| sbwhart:
Very nice build, it should work out to be a powerful engine, some of the guys my loco club run 5" gauge Tiches very sucesfully Stew |
| GWRdriver:
Page 2 One of the challenges of technical writing is maintaining a logical continuity, where one action is followed by its logical successor, a straight-line progression of action, when in fact technical progress is typically anything but straightforward so there may be some skipping around. A number of things influence the selection of this locomotive project. I chose 7.5" gauge because the nearest available tracks to me are 7.5" gauge. I chose a British 0-4-0 because firstly I love British locos, and then as I mentioned previously I wanted something I could build quickly. Tools can also play a large role in project choice so I'll list mine to give you an idea of what I have to work with: Lathe: Harrison 10"x24", Mill: Jet 8" x 30" combination horiz/vert, drill press, die filer, cutoff bandsaw, 1x42" belt grinder, oxy/acetyl torch, and the other miscellaneous gear and accessories as would typically go along with these machines. One item which has been particularly useful is a heavy 9" rotary table (Troyke). I acquired my tools piece-meal over a span of 30 years and they give me the capacity to easily build a 7.5" gauge locomotive. I don't use CNC or insert tooling (yet) and my one "modern" indulgence is a DRO on my mill. My most often used workshop tool is a file. Occasionally I will do some job the hard way, that is, I'll use a material or technique that I could easily have done differently and saved time. My answer to that is that I often do things to challenge myself, to see if my skills are up to snuff or to develop new skills. Most times I'm glad I tried it out or acquired a new skill, but sometimes not, and I'll try to tell you which times are which. It was also important for me to be able to say, in the end, that I built it all myself, within my own workshop, and so far with the exception of the casting I haven't put anything out to be done by others. There are a couple of things that will need to be MIG or TIG welded and that will have to be put out. Some years ago I had the opportunity to buy a few odd castings for the BRIDGET loco (mentioned above) and these included a set of drive wheel castings and cylinders which were very close to the size needed for the TICH, although the BRIDGET driver castings were 5" diameter and the TICH called for a 4" driver. So the decision was made to re-scale the original TICH to accommodate oversize drivers and in the end the loco is very little over the overall size of the original. The cylinders however did not work out well so I decided to make a pattern for the cylinders and have those poured in cast iron. I would have made many more patterns for iron castings over the course of the project but in my area walk-in, loose pattern iron foundries are a thing of the past. More on the cylinders much later on. A full set of original drawings for the 7.5" gauge version was acquired from GLR in the UK and start was made. I began redrawing in Cad (Autocad Ver.LT97) and a plank 1/4" HRS (hot rolled mild steel) plate was bought to make the plate frames. The original drawings call for 5/32" plate but 1/4" actually cost me less and it would add weight on the drivers which any 0-4-0 can always use more of. Many things on this model are heavier than necessary and in almost very case it was a matter of being able to add weight for little or no more cost or trouble. I began by rough-sawing the frame plates to size on the cutoff bandsaw (in upright position) and the two rough plates were dressed (filed) and matched up. I then drilled through in several paces which I knew would later be cut away (or enlarged) for bolting holes. Two holes located in opposite ends of the pates were reamed for dowel pins so that if the frames needed to be separated, as they would be many times, the dowel pins would make certain the plates lined up exactly when machining continued. First the frames were clamped in the mill and all edges, slots, offsets, etc, were finish milled. With the frames mounted squared in the mill, critical holes for shafts, screws, pins, etc, were indicated in and drilled or bored. The axlebox slots were chain-drilled and bandsawed out (Photo-1) and the finished axlebox slots were indicated in and milled out (Photo 2). In Photo 2 you can see a set of axlebox horns being try-fitted in a slot, but that is getting ahead of the story. Drilling and countersinking (when necessary) for most bolt and rivet holes was done and the frame plates were essentially complete. Some holes were not drilled at this time because the exact locations various things remain to be decided and much of this will be decided by try & fit. Some already drilled holes will not be used and will be filled. Photo 3 - a finished frame held by Your Humble Servant, although as you can see horns, axleboxes, and pedestal caps had been added by the time this picture was taken. If anyone wants more detail or information on, or to discuss anything I have or will describe in this thread I'll be more than happy to do that, but to keep this thread easier to follow I'll do that on the How To board. |
| NickG:
Nice work GWR driver, I've always liked tich but the 3 1/2" version was just too small, I can imagine the 7 1/4" being a great performer though. I live in Co. Durham, not heard of Ken Swan but I knows somebody else in our club who built a bridget, i've drove it on several occasions but unfortunately the guy eventually became too old to keep coming to our club. Shame as he was a brilliant engineer and a lovely guy. His bridget engine was extremely powerful, infact all of his engines were - no bling but just extremely well made. Nick |
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