L1 new build

If a screw reverser worked satisfactorily for passenger work and a lever for shunting then why would there be a need for something more complex with a greater maintenance overhead? Churchward, for instance, dropped steam reverse which was fitted on a number of the late Dean period classes, Bulldogs, Cities Aberdares and the like.

 

Both have a maintenance overhead. Do you know which was greater? I don't.

The G&SWR found their power reverser (not the Swindon design, which may well have been problematic) cheaper and more efficient for something like 50 years under successive competent engineers. Their crews were appalled when they started receiving 'modern' LMS engines with lever reverse!

Edit - And of course if your manual reverse is so difficult and/or dangerous to operate that it encourages crews to operate the loco inefficiently due to the effort and risk involved in operating the thing at speed, then there is a cost in fuel and water as well. Many examples can be quoted about the difficulty on some engines of notching up lever reverse at speed, or of screw reverse flying into full forward gear if the catch was loosened to adjust the cut-off.

 

Have you ever been on the footplate of a GWR engine with a lever reverse?

The advantages of a power reverser that I can see (at least one that works well) are:

1) Reduction in physical effort / fatigue for a crew over a long day
2) Increase in space in the cab.
3) Ability to change cut-off while the regulator is open (you can do this with a screw reverse, but it can be very hard with a lever reverse, which sometimes requires that you momentarily shut off while notching up).

GWR tank engines (which tend to have small cabs anyway) can be very difficult to get in and out of as the reverser quadrant often blocks some of the cab door space! I guess their crew were selected from midgets...

I wonder as well about the cost overhead. There is probably an increase in maintenance overhead for a steam reverser (extra lubrication etc at the beginning of the day, more oil consumption). However, for a screw reverser at least, they are also quite complex bits of kit to manufacture, typically requiring some combination of multi-start threaded shaft, threaded die block, locking and anti-shock mechanism etc. Whereas a Stirling reverser is essentially two cylinders (one oil, one steam) with their pistons connected on a common shaft, and a couple of control valves (one steam, one oil). So I wonder what the difference in first cost would be?

Incidentally, all the NZ locos I have been on have had power reversers as well, though using compressed air rather than steam as the working fluid.

Tom

 

so what kind of steam reverser did an L1 have again ?

 

Southern L1? Ashford one I think (a descendant of the G&SWR one as mentioned above)

 

Right, i get it now.

 

This really only applies to slide valves. Lever reverse with piston valves is usually quite easy to do. Certainly that is the case with the lever reverse GWR piston valve locos I have experience of. No need to shut the regulator; in fact it is quite easy to hold the lever steady in any position that you desire without having to put it in a notch. However, as you say the levers on GW tanks do tend to get in the way when in reverse.

 

Most modern US locos have some form of power reverser - I think in some cases using compressed air rather than steam, but I may again be talking utter bollox. I recall reading some manner of interview with or reminiscence by OVSB in which he made the claim that Eastleigh insisted on using the Drummond rather than Stirling reverser.

Incidentally, as and when I achieve my dream of buying a Merchant Navy and restoring it to original as-built condition (with detail improvements here and there), could a Stirling-type reverser be incorporated in place of the Drummond one? What's the major difference between them, other than their function?

 

Sorry, I meant to ask when the thread was topical, but were the steam reverser's shortcomings responsible for the demise of Fighter Command, which I understand went into reverse at high speed?

Also apologies if this has been discussed before, and also not really L1 related.

 

Any news on the L1 Stuart? Must be nearly finished now...

 

Would that be the LNER or the SR one?
Ray.

 

Silly question. One of each of course!

Sent from my KFTT using Tapatalk

 

Both L1s are complete. As is the J39. I believe his 2859 from Llangollen is also well on the way to steaming and he is soon to be knighted for his work in preservation.

 

Hornby, its a Triang rebuild.

 

Are they being kept in the same shed as Newstead?

 

Nah they're going straight to box tunnel to join the strategic reserve...

 

One of the less attractive aspects of the net is flash mob mocking of the afflicted.

 

It's fairly obvious that this project was a stage or two below non-starter, but feels a little bit mean to bump the thread again just to mock the lad... Unless I've missed something?


Sent from my iPhone using Tapatalk