614 operating question

mxdata · **Joined:** Thu Jun 16, 2005 11:54 am **Posts:** 609

That's great information Ross, Thanks! Any work that you don't need to do is good news.

whodom · **Posted:** Thu Jan 19, 2006 11:16 am

mxdata wrote:

On the question of how you would prevent a steam locomotive from "taking power" (in diesel terminology), this could be done too, without too much sophistication. I have seen suitable rigs used in a variety of non-railroad applications. It would require a sliding link (maybe a rod and tube arrangement) with a disconnect solenoid, applied to the existing control linkage, and a positioning device, like an air cylinder. Once the normal control end of the linkage has been disconnected by the solenoid, the cylinder would force the disconnected end of the linkage to the penalty position. The cylinder would not normally have to be connected to the mechanical linkage, it could just push against a stub welded to the linkage. If you wanted to center the power reverse gear you might want two cylinders working in opposition to each other, to make sure the power reverse goes to actual centered position. Any necessary timing for applying the control movement to "penalty" position could be provided by a small PLC or possibly even a small relay logic switching system, since you would already have suitable control voltage available. Another possibility for control of the penalty timing would be to regulate it pneumatically through the use of volume reservoirs, check valves, and chokes.

This is an interesting discussion and is relevant to future steam operations. Some of you may have heard of the project in the UK to build a new, modern steam locomotive for excursion service, the 5AT. Basically it's a British Rail Class 5 4-6-0 (~1950 design) brought up to current engineering standards, incorporating advances in materials and design techniques. It's not intended to be a direct diesel replacement (like Ross' ACE 3000 project), but a better alternative for mainline operations than using a ~70 year old steamer.

One of the hurdles the 5AT group is facing is complying with current UK railway regulations, the Railway Group Standards. One of these (RGS RT2045) requires that "Either a full service or emergency brake application shall automatically inhibit or interupt traction power". The method you outline above sounds like exactly what they need to accomplish this for their locomotive.

Note that the potential problem that Ross mentions (closure of throttle interupting valve & cylinder lubrication) will not be a problem with this engine as the lubricators will supply oil directlly to the rubbing faces of the valve chambers and cylinders. This lubrication method was successfully used on late German steam locomotives, and by all indications is a superior method to provide lubrication in any steamer with a high level of superheat.

Read more at the 5AT project website at http://www.5at.co.uk

Dave · **Posted:** Thu Jan 19, 2006 11:46 am

That problem can also be overcome by installing a seperate very small steam circuit (including atomizers) in the lubrication system feeding the cylinders - sort of like making the mechanical act like a hydrostatic by assuring a constant stream of low temperature oily steam independent of throttle setting.

dave

mxdata · **Joined:** Thu Jun 16, 2005 11:54 am **Posts:** 609

Hugh, thanks for your comment. One additional note I should have added to my original posting is that by using this type of a linkage disconnect, you would have to move the normal control end to match the final "penalty" position of the rest of the linkage to allow the solenoid to re-engage. This serves to "acknowledge" the penalty.