Confused, John - if you haven't made a test run, how can the results be proven? Some sort of static test? I'd like to test the exhaust on 12 as is to try to set some of the values that could be used for an improved design, and if you have a static test technique it would be very helpful.

dave

Yes, the exhaust sound on a Lempor equipped locomotive will be different - quieter since there are no longer any mini-sonic booms going on inside the smokebox.

David Wardale's original 4-8-2 conversion in South Africa I believe was nicknamed "Spooky" because it was eerily quieter than its sisters.

In case you were worried about losing that thunderous exhaust many folks like hearing - don't be. While the exhaust is quieter, it still makes itself known...

Wolf

I have heard 29 after the conversion, she still has a decent bark to her.

The previous post contained an inaccuracy. Here is some clarification on the action of the Lempor exhaust. The purpose of any exhaust nozzle is to create a vacuum in the smokebox. This vacuum pulls air into the fire, and the products of combustion through the tubes. As Wolf stated, basically, smokebox vacuum is formed from the Bernoulli effect of a rapidly moving stream of steam. This is an example of the "ejector" principle. Basically, the nozzle, petticoat and stack form an air pump with no moving parts (similar to an injector). All devices, including this pump, consume energy. In this case, the energy is supplied by the exhaust steam, so the statement that a Lempor "sucks" steam out of the cylinder is TOTALLY inaccurate. That would be a form of perpetual motion. What an exhaust nozzle does is convert the energy contained in steam in the form of pressure into energy in the form of velocity. As with all man-made energy conversion processes, this conversion is not 100% efficient, and some devices perform the conversion more efficiently than others. The traditional "bridge" nozzle was more efficient than the simple orfice used before it, the Kiesel nozzle was more efficient than the bridge, and the Lempor is the most efficient designed to date (that I'm aware of). It takes advantage of the massive leaps forward in our knowledge of fluid dynamics that have taken place since the 1940s. By applying proper fluid dynamics principles to nozzle design, steam can be accelerated from rest more effeciently. If the steam is accelerated more efficiently, less energy is required to accelerate the steam, and a lower back pressure is needed to form the same amount of smokebox vacuum. Hope this helps.
-Stu

Mr Rimmasch,

Has there been any further progress on the 3985 since this WRC update in early October?

http://projects.wasatch-rr-contractors.com/?page_id=193

Thank you

TH

Trevor, thanks for asking!

The work that WRC has done to the Challenger is finished. The UP shop staff is now completing a few finishing details to the running gear and the fire box. I saw the locomotive just last week and the finishing work is progressing well. I would suspect that we will see the Challenger this spring.

Keep watching the WRC page for spring test runs. We will be watching our work very closely!

www.wasatch-rr-contractors.com

Merry Christmas from all of us at WRC

JohnE.

Pardon my ignorance, but I can't see how front end modifications can possibly cause failure of running gear.

Regardless of what is in the front end, or what the valve gear does, surely the greatest load on gudgeon pins, piston rod fit and crank pins occurs when the locomotive is stationary and the throttle wide open. regardless of how fast the steam gets into the cylinder, it will eventually build up to boiler pressure and with no motion, there's no back pressure.

The maximum possible force is thus dependent on cylinder diameter and boiler pressure. No more; no less. Surely this is what determines if anything will break.

I fully understand that more power can be got out of the loco; with reduced back pressure there's more effective pressure and more draft means more ability to supply steam. Yes, powering forces at a given speed will be higher than before - but surely never more than the static case. I can't see how the dynamic loads (due to parts whirling around and reciprocating of rods are any more either; There's surely as much dynamic load whether powering or coasting at speed.

The real issue has got to be that more power at higher speeds leads to lubrication problems and possible heat dissipation in bearing problems.

Or am I wrong?

John,

Thanks much for posting that update. At least some of us will be watching for further details with great interest.

Merry Christmas!

In regard to the running gear work. The work that is being done has nothing to do with the front end work and the fire box work. The locomotive was due for new tires, which it received as well as some other needed running gear work.

When Mr. Lee and his team at UP design work schedules they do as much as they can with the budget and time that they have. As such, there were many projects on the board for the 3985. When it does come out for testing there will be much observation in a variety of areas on the locomotive.

Your comments are sound. Not to fret, the front end and the running gear are not related........at least at this stage........stay tuned!

www.wasatch-rr-contractors.com

John E. Rimmasch

Mr Rimmasch,

Thank you for the reply.

Do you have any more detailed images of the LemPor installation? It certainly looks like some fine workmanship.

Clearly on such a locomotive you are after improved combustion (read reduction in fuel consumption and black smoke) at a time when both are under increased scrutiny, not more power correct?

Thank you

Trevor Heath

The link below is a 6 minute video taken inside the UP steam shop in Cheyenne.

The video jumps around but it does show some of the new stay bolt clusters on the outside of the firebox of 3985 but nothing on the inside of the replacement platework

The last 20 seconds give a clear view of the LemPor exhaust installation.

http://www.youtube.com/watch?v=D69dQBgFZlk

TH

3985 was out on the main line yesterday. Looking forward to hearing how the test run went.

TH

Same here - is this a first for the Double Lempor?

Would love to see some performance data from this, John keep us posted!

Edit - removed redundant question...

I'm pretty sure it's the first retrofit for a double Lempor (existing double stack exhaust replaced with a double Lempor exhaust). Both of David Wardale's locomotives in South Africa (19D 4-8-2 no. 2644 and 26 4-8-4 no. 3450) replaced stock single stack exhausts with double Lempors. David's design for an improved Chinese QJ 2-10-2 would have featured a triple Lempor.

Posted above was this question. Also the answer that affirmed that Nigel Day indeed was consulting.