Hello,

In the summer of 1985, in the midst of my senior at school, I had a summer internship with my first employer in their foundry. We poured very many grey iron castings and a few large stainless steel castings up to 2000-3000 lb. Casting stainless was extremely challenging, porosity was a huge problem. Many times, the porosity was gouged out with an air arc and filled with weld. a very costly, time consuming process. For my internship I was involved with developing a database of mold preps which needed done for the castings. It seemed and I was told the whole process was a "black art". Personal experience and opinion of the molding supervisor was the basis, which seemed highly subjective. I recall steel had a more aggressive shrink rate than grey iron. Where to place risers, chaplets, were documented in routers to try to gauge mold labor estimates and costs.

Since then, perhaps there has been advances in molding technology, maybe FEA, CFD? or maybe that is a stretch. At least solid modeling opens the door to these additional options.

Steel casting seemed to add an additional level of challenge and difficulty to the casting process. Add to that, built up cooling stresses may need a post-cast stress relief prior to starting any machining. We did multiple stress relieving operations in some cases.

Kudos to the T1 Trust and it looks like they are making interesting progress. Best wishes to them and hopefully they have the will to stick with this for a very long and complex process.

Regards,

Randy

You assume that no one on the T1 team has any foundry experience.

I could understand that the foundry wants the work done in house. If the work is done in house, would not the foundry eat the cost of any mistakes, so long as the design of the finished product is sound?

In response to others' posts, yes, CNC is becoming very commonplace in the pattern shop. I am somewhat surprised the pattern is being made of wood... To create eight drivers may take a toll on the wood pattern. But then again, do we know what the next step in the process is? They could use the wood pattern to create a silicone mold, then pour an urethane/epoxy pattern.

I'm actually pretty interested in this group's progress in this endeavor, and look forward to seeing the end result.

Mike Walsh

Have they indicated how they will build the main frame? Seems to be at the heart of this project. Everything else can be made; it's just a matter of money and actually doing it. The huge, complex one-piece original frame with cylinders, etc. would be a problem nowadays.

As has been said by me and others, it would likely make sense to divide it into segments and use modern welding techniques to assemble it and avoiding losing a lot of time and money on failed attempts to do it in one pour. But it would take some engineering to determine the best places to divide it and design the mating surfaces in the best way for later joining.

With the production of the drivers, is the plan to continue right along with the production of all other parts in close succession? If so, I assume that several parts will be in production at the same time. Is there work currently underway on many other parts?

A quick Google search will show that there are lots of huge steel castings being produced today. The technology is probably BETTER today than it was back in the 1930's and -40's. This is not to say that making something like this will not be difficult and expensive, just that there are companies out there for whom a cast steel locomotive frame would be just another job. Just remember that the Austin Stem Train got several new steel castings for their SP786, including a new cylinder saddle.

I'll say it again - technologically, there's never been a better time to build a new steam locomotive. Economically, few worse since the 1960s.