Requesting advice on GWR King 5"

[vincemartyn]

I have a 5" King to the Perrier/Spinks design that an experienced engineer has completed for me. I am still learning!

I put a video up of it in a group and the guys advised me that it sounds like the piston rings and/or valve bobbins are leaking. It is a hungry engine and needs plenty of coal to keep it running. A friend who has fired the full size engine says this one is just as hungry. One suggestion was that I could do with the knowledge of Don Ashton who would be on here, so hopeful that Don can comment.

I was going to upload the video but at 3Mb it's too big for attaching, you can get it here... www.martyns.net/king2.avi

I do recall my simplex getting hungry and throaty when that needed the graphite packing (in place of rings) replacing and am now wondering about the King. It has PTFE rings in it at the moment.

Vince.

[Deleted]

welcome to the forum Vince...Don was online earlier and I'm sure he will respond once he see's your plight...others here should be able to help too...Julian knows an awful lot about GWR locomotives as do others....alas our other great man for this, Peter Rich fondly known as 'taff' passed away some months ago..he will be greatly missed

regards

Pete

[vincemartyn]

Thanks Pete,

I have started looking round and think I will spend more time on here. I will invite a friend too. It's great to find such a site!

If anyone visited the GDSF model tent last year, our King was there.

Vince.

[Deleted]

this is a great site with some very knowledgeable folk.....friendly bunch too...well mostly.....

Pete

[jma1009]

hi vince,

welcome to the forum. always nice to see some GWR locos.

i had great difficulty viewing your clip and it is a very short clip, but it was immediately obvious what the problem was.

i dont know how to put this politely but i am sorry to say the loco sounds knackered. it is making very heavy weather of pulling just one person. the exhaust indicates quite clearly that the piston valves are blowing very badly. i dont expect the piston rings in the cylinder bores are too good either.

it will probably require a huge strip down job with the boiler and smokebox removed disconnecting the rear of the inside cylinder valve gear linkeage and crossheads will be quite an awkward difficult job. it is also quite likely that the horizontal motion plate will have to be removed to gain access to the parts that need disconnecting.

cheers,
julian

[vincemartyn]

Thanks for breaking it to me gently Julian

Looks like it's going back to the guy who did the work.

Vince.

[jma1009]

hi vince,
please dont take just my word for it.
there is a very well known procedure/test in fullsize and applies equally well in miniature for checking whether valves and pistons are blowing. it is set out on p.95 of 'Handbook for railway steam locomotive enginemen' (the old BR handbook reprinted by Ian Allan).
cheers,
julian

[vincemartyn]

Hi,

I have ordered a copy.

Thanks
Vince.

[Deleted]

Hello Vince and welcome aboard me heartie to you from an Ex-pat Reading man (Southcote) now fully absorbed into the Shropshire way of life !!..........Yes, there is a very noticeable "Rasp" to the exhaust isn't there ??............. You should be able to pull at least 10 to 15 adults with ease along with 4 sharp, even beats to the exhaust ( Churchward's 4-cylinder designs had two cylinders exhausting at the same time so it sounds like a 2-cylinder loco...). In my copy of "The Black Book" on page 95, section 11 I think there is a mis-print where it calls for the drains to be closed but then goes on to say}----"noting the indications given at chimney or drain cocks"..........I seem to remember the late Ray Tranter instructing us at Bridgnorth SVR on a Hall, and the drains were open such that you can tell if indeed a ring was leaking or not..............As Julian mentions, access to the inner parts is quite complex but not impossible..... I'm not familiar with the Perrier design as such and wonder if it originally specified Iron rings ??.. If that were the case then a change to PTFE without any mods. may well be the cause ?...Just a thought...............PS}-- I was a Diesel Fitter at the old Cow Lane Depot before moving up here....Do the names George Stares or Bert Pace ring a bell ??............ Finally, what's happened to Smiffy ??.... He used to post quite regularly on here with updates on his 5" Royal Scot build ....Do please keep us informed..........Alan R

[vincemartyn]

Hi, Thanks for the advice. Unfortunately I don't know George or Bert. I did get a visit into the depot at Cow Lane a few years ago when I was interested in modelling a DMU which were based there. A great few hours that I will always remember.

I am waiting for my handbook.

Vince.

[donashton]

Hello Vince, and Welcome,

There are things to ponder! Julian doesn't like giving pain to anyone, but many of the faults should have been tested and fixed in the earlier chassis stages and Julian will undoubtedly be proved correct.

My first thought is that there will be a mountain of work to arrive at satisfaction - what is the point of returning it to someone who didn't get it anywhere near right in the first place? Those cylinders should have been tested before fitting on the frames. The video clearly shouts that characteristic hollow sound of leakage and it's far too great. A King should pull 44 passengers, not 14! A complete strip down of all cylinders is required and bores/pistons/valves properly verified as tight. There really isn't a short cut. PTFE is not a panacea allowing poor work just where the best is required, as so many modellers seem to think - please note.

A hopeful sign - there is quite a strong beat cutting through the noise which sounds reasonably even, so the valve gear and timing could well be OK. I'm not familiar with Perrier's King design, but most are faulty to some degree. The BR Handbook should certainly be on your shelf but remember that the wisdom of its pages apply to something that was made properly in the first place. You are needing to discover where are leaks and why.

Sorry this is a tale of woe but the magic wand is out on loan somewhere - can't think who had it last!

Don.

[gwr7800]

Hello Vince and welcome to the forum,I've got nothing to add to the experts finding, however just a quick question how long have you had your King? How long from when you received it from the chap who built it did this happen, or has it always been like this? I agree with Don it wouldn't be my first choice to send it back to the person that did it in the first place, just my opinion! Good luck in your rebuild! Would be very interesting to see pictures if you decide to have a go regards Chris

[Roger]

Hi Vince, it's good to see you here. I'm relatively new here too and have found the expert advice to be freely given and extremely helpful even if it's not always what I want to hear! Maybe this is the time to take stock and roll your sleeves up. With the help you'll find here, I'm sure you can get to grips with the issues your locomotive has and end up not only with a wonderful performer, but with the knowledge to keep it that way. I'm never happy leaving things to others to get right, they rarely go the extra mile if that's what's required and I always feel like a hostage to their ignorance/expertise. (delete as appropriate)

[Deleted]

Hello all------- Hi Don, I hope you are feeling a bit better from when we last met ??......OK, maybe I was being a bit "Economical with the truth" ??....but I think we are all in agreement that Vince's engine is decidedly "Poorly" ??...... and that characteristic wheezing sound is indeed indicative of a ring or rings passing steam ( Coupled with it's high appetite for water and coal ) ......... Does anyone on here own ( or have access to..) a set of Perrier drawings ??---------- and if so can you post a photo of the cylinder design, especially with regards to the ports shape - I'm taking it for granted that it is a Piston Valve loco ??...........Vince, might I ask how much of a beginner are you with respect to the mechanics of these engines ??...... ( That's just so we know at what level to pitch a Tech. reply...).....

[vincemartyn]

I am not a complete beginner. Before the King I owned and ran a Simplex for a number of years, so I know how things work but don't yet get some of the intricate points. For example I understand cutoff and what it does but can't explain how the linkages of the motion achieve the end result and which direction the engine is going to go in just from the linkages. I understand that the two sides of the engine are 90 degrees apart so that there is always a cylinder on the power stroke. The handbook will help me gel some of this together as I expect this page of diagnostics that people are talking about will make me think about the interactions of the piston valves and where the steam comes out of the drain cocks.

Yes the design is 4 cylinder with piston valves. The cylinders on each side run in tandem, so really it's a two cylinder engine with ideas of grandeur!

The guy that finished the build is a well respected member of the club. He can be heard on the video. I am sure he would fix it. This video is from one of the first runs of the loco, so it's been like this all the time.

Thanks for the help!

Vince.

[donashton]

Hi Vince,

So more than one has worked on the build? That's not a good recipe for such a complex engine. I wish for your sake that less than a big strip down.....but that would be silly. From a brief video it is hard to be conclusive, but the faults appear to be basic leakages in the cylinders.
1) Bite the bullet and strip down.
2) Find and correct the leakage.
3) Test each cylinder before fitting.
4) Air test (steam if you can have this luxury)in chassis form.
5) If results of 4) are not good, or you even fear a hunch somewhere, sort this out before reboilering.

I see that the forum dictionary doesn't like the common verb 'to reboiler'....I reboiler, You reboiler, It reboilers....Wonder what Catalan Joan would say!

Big job Vince, but what a reward for perseverence. And plenty of guys with answers as you go.
Cheers,
Don.

[smallbrother]

I can't view the video on my crap PC and I don't claim to be able to judge the faults in any case.

Seems to me you need to refer things back to the "experienced engineer" asap, as the advice from the experts clearly indicates fundamental problems. Sounds like you are at a similar level of expertise to me, which is not very far up the scale!

Pete.

[Deleted]

千里之行，始於足下 (zh)-----

[dem132]

Reading this thread with interest, I shall also buy a copy of the hand book as well. I've also located a downloadable version of this, not sure whether it's breaking any copyrights etc. Normal disclaimers.....

Download it as a adobe pdf:

Handbook For Railway Steam Locomotive Enginemen

[Shawki Shlemon]

I built one of these 10 years ago , leaking may be the problem but there is another important issue , Walschaerts valve gear is driven by eccentrics on the front axle , the offset is predetermined , basically timing is back to front and the outer cylinders valves are driven from the inside cylinders , all this is very critical and very hard to time ( at least for me ) . I sold the engine 6 years ago .My engine run reasonably well for a long time but I heard that eventually he re timed the valves , I don't know what he did and since he has sold the engine as he needed money for business , as far as I know it is running well . for valve pistons I used PTFE bobbins and for cylinder pistons I used PTFE rings .You can see it here members.dodo.com.au/~shawki/dodo.com.au/GWR.html