RUSSELL returns to WHHR

If anything the master mechanics style spark arrestors help to even out the gas flow through the tubes improving steaming. The Ffestiniog engines all use this style with no loss in performance including on Linda. There should be no need to fit a Lempor exhuast.

Tim

 

I am sure I am wrong in this particular case but I tend to detect a little "not invented here" reaction to Lempor.

P.H.

 

Lempor isn't the only option for a more efficient exhaust. K&ESR have reported good results on at least two locos (a USA and an Austerity) with their own multi jet design.

 

Linda was fitted with lempor, now removed. 87 still has one I believe. It is not a case of not invented here, it is a case of tried here and found not to be as beneficial as other things for the same effort / expense. This is just part of the continuing evolution of the loco fleet.

Regards

Peter

 

Generally the effectiveness of an exhaust as a draught producing device depends on the height available from blast nozzle to chimney top to a large extent, and there the NG often has an advantage over SG locos as can be seen by the relative height of their chimneys. So on SG loco's a multiple (normally double) chimney will normally outperform a single chimney as the height required for good efficiency is less as you halve the flow per chimney etc.

That said, there's also the back pressure on the cylinders to consider, and here a properly designed multi-jet will outperform a single jet no matter what the gauge, imposing a lower back-pressure and so increasing cylinder efficiency for the same draught.

Lempors are well understood, but other devices are also available as they say.

 

It is known to stick a chimney in the chimney to help with lighting up first thing which goes to confirm your first line..

 

I was once informed that narrow gauge engines tend to have larger ports in relation to cylinder sizes than standard gauge machines but, of course, this is impossible to generalise. One recalls that instead of fitting double chimneys to all A4's the "powers that be" had to be dissuaded from removing them from those that had. "Don't hold with that" has a long and inglorious history.

PH

 

Sorry but the blast nozzle/chimney height ratio plays no part in the 'lighting up' situation. An extension chimney simply provides more natural draught (as distinct from blast) by convection. As the hot gases rise up the chimney more air is drawn through the fire-bed increasing the rate of combustion. It also reduces the amount of smoke 'blowing back' into the cab. Hope this helps. Ray.

 

No need to be sorry, i was out of my depth, interesting method though which is not common.

 

A spark arrestor is just that. It, by it's very nature places extra demands on the exhaust system. You can measure the vacuum both upstream and downstream of the arrestor. It is a source of vacuum loss that has to be accounted for. Carry over of particles from the firebox entrained in the gas flow are a major source of loss of efficiency. To say nothing about the spark problem.
The design of firebox and the choice of combustion system is fundamental in driving efficiency and power output. The spark arrestor is an unfortunate necessity. Ideally you would have no spark arrestor if you could avoid it but this ideal has to date proved impossible to achieve with the burning of solid fuels.
As most original exhaust systems are poor, to say the very least, any effort expended on an improvement is quite frequently rewarded with some level of improvement. In some instances the improvement is a false one. Steaming improves against an increase in back pressure for example. Given the amount of information available today there is no need for the use of third rate exhaust systems even though these are an improvement on the fourth rate originals. Only the very best should apply.

 

Several posts removed, please refer to forum rules, naming people who may not be on the forum and attaching roles or statements to them without factual basis is not allowed.
If an evidence source can be quoted the posts can be relisted.

 

Can anyone from the WHHR confirm whether Russell will have vacuum brake grear fitted upon return from overhaul? I gather it was removed some years ago. And are any of the WHHR carriages dual braked, or air only?

 

My understanding is that RUSSELL will only be air fitted on his return. The vac Brake equipment was perviously installed in the drivers side coal bunker and this space will be needed for coal if/when RUSSELL runs extended trips on the restored WHR.

All coaching stock on WHHR is single pipe air only. We have run Vac stock (borrowed from the FR) at special events most recently at Quarrypower with LILLA in 2012 and when ISAAC and GELERT ran together in 2013. We have also through piped an air braked vehicle to run sandwiched between two pieces of vac braked stock (PALMERSTON's visit in 2000.)