7¼" gauge in the garden

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7¼" gauge in the garden

Locomotives - POEM

 

Other pages of interest about POEM: Workshop, The 2008 Diary and

POEM Galleries: Squirrel Valley, June 2008    Manu Arik,i March 2009    Hamilton ME, March 2009

  A "Baldwin-style" 2-8-0T+T (combined side tank and tender loco) built by Murray Lane, Auckland, NZ.

POEM was designed for a railway at Manu Ariki Marae a few miles north of Taumarunui in the central north island of New Zealand. She was to be able to haul a load of 54 adults up their 1 in 100 gradient, including a short stretch of 1 in 40 on a bend. Due to a lack of suitably trained staff at the line they decided not to buy the loco in the end and Murray retained her for himself. The railway is still open and now extends to just over 3km (just under 2 miles), or a 25 minute run.


  • POEM is unusual in that the builder (Murray Lane) combined features of several different locos to build this one. It is vaguely reminiscent of a World War I American ALCO or Baldwin trench loco, but it is a 2-8-0, not a 2-6-2.
  • POEM is a combined side tank and tender loco making it more like a sugar-cane loco. There were no eight-coupled sugar-cane locos in Fiji, though there were still a few in Java (as of 2006 and most of those were German-built).
  • POEM uses Allan straight-link valve motion, which was unusual on full-size locos and even rarer on miniature locomotives.
  • POEM will have to be repainted, it simply doesn't look right to have a blue and purple steam loco. That said, many of the sugar-cane locos in Java (and Australia) were painted some fairly garish colours.

Murray was originally going to build a model of Palm Oil Estates Management (P.O.E.M.) railway locomotive #3 but she would've been too small for the intended use so he changed the design to the semi-freelance 2-8-0; but he kept the name POEM.

Murray said that POEM has been running for about five or six years and he has rebuilt those parts that were not satisfactory, so there is little chance of it developing a fault that he hasn't already uncovered. For instance he re-made slide valves as the original phosphor-bronze ones distorted and he made new cast-iron ones. Murray is a superb engineer and there is no faulting his workmanship.

This is a loco built for hard use and is not a finescale model. The paintwork is a bit tarnished in places but the underlying loco is in very good condition.

 
 

Specifications

Mechanical

Wheel arrangement 2-8-0
Cylinder bore & stroke 70 x 94mm
Length of engine 2085mm
Total length with tender 3675mm
Height 900mm
Width 600mm
Engine weight empty 490kg
Engine weight loaded 567kg
Tender weight empty 180kg
Tender weight loaded 360kg
Wheel diameter - driver 166mm
Wheel diameter - pony truck 114mm
Wheel diameter - tender 275mm
Fixed wheelbase 615mm
Water capacity 120 litres
Coal capacity 35kg
Boiler
Type Briggs
Capacity 30 litres
Internal diameter 200mm
Total length 1200mm
Length between tube plates 843mm
Grate size 300 x 294mm
Fire tubes (20 off) 19mm OD
Ash pan 330 x 320 x 100mm

  I will probably repaint POEM in the same scheme as VICTORY on the Bredgar & Wormshill Light Railway.

I may also take the opportunity move the headlight to the top of the smokebox and to rename her (to PETER after my father). If I do, I might move the nameplates to the side-tanks.


John Bremner and I spent an hour or so discussing our discoveries so far on POEM.

  • There is some quite bad surface rust under the flare on the tender sides. This will need to be rubbed down and repainted.
  • John made up a prototype (crude) replacement bracket for the regulator that swaps the pivot and rod holes around thus making the regulator work the "correct" way.
  • After a quick chat with John he made up a new headlight bracket to mount it on top of the smokebox.
  • The chimney looks slightly too short to my eyes.
  • Both John and I agree that the cab sides are too low. We're looking at options to raise the floor of the cab to the tops of the frame - about 70mm. This should make the proportions about right for the Baldwin/ALCO originals.

August 2008

  POEM's new headlight bracket is done and I have turned down all of the brass valves. We just need to finish fitting the coiled wire grips.

We managed to get the cap and base off of the chimney tube. I am going to raise the chimney by 35mm to be more in-line with the top of the cab - it is a bit "dumpy" at the moment.

We took the cab off and will make a start to raise the footplate. This will help raise all the pipe work up off the ground too and make the whole loco look more balanced.

The chimney is done. We've actually cut the tube longer than originally planned; the proportions of the chimney look so much better. Once the cab is back on we can re-assess the height of the chimney and if necessary trim a bit off of the top; taking the brass cap off is easy enough. Checking with prototype photos, the chimney should be higher than the top of the cab by about the diameter of the chimney barrel.

POEM's new, higher chimney and relocated headlight. Notice in the photos above that the base of the brass cap is roughly level with the top of the dome. We all think the proportions look much better now, but once the cab is back on we can always trim a bit off of the barrel to lower it if we need to.

  Interestingly, John took one of the side tanks off and POEM looks rather nice as a tender loco!
  John and Grant are contemplating the new footplate - which has been raised at the sides.

September 2008

  John Bremner performing somewhat "brutal" engineering on POEM's cab - I didn't have the nerve to do it myself and John does this sort of thing all the time, so "leave it to the experts" I say!
  This is POEM's cab tested-fitted back on (compare the shot below to see how much of the cab has been pruned away). We need to re-fit all of the pipework, injectors etc. under the cab, but a strip down and re-paint is going to be next.

Having seen how it's worked out, we'll probably trim about 20mm out of the barrel of the chimney.

 

We are making progress. All of the pipework on the righthand side is back on. It looks a lot neater and is up out of the way of the track. we're now working on the lefthand side. After that it is a bit of a tidy up and we take the boiler cladding off to go for painting along with the side tanks, cab and tender body.

I'll get the chassis steam-cleaned and then we can go around and touch-up the black. I am not prepared to strip the whole loco down to do a bare-metal repaint, it doesn't need it and it is a heck of a lot of work.

October & November 2008

 

Not done much recently as I have helped John Bremner move premises, so POEM has taken a bit of a back-seat.

December 2008 & January 2009

 

John B. and I made good progress over the holiday and POEM is almost ready for a steam test. Once completed, we'll (partly) strip her down to be repainted. All being well, she should be back on the rails in a few weeks.

I just ordered some new brass gauges from Miniature Pressure Gauge Ltd. (www.miniaturepressuregauge.com). They were the only company I could find who would do a 3" diameter, 0-150 psi steam gauge. Their prices are good too.

We steam-tested POEM last night after her overhaul. There were a few minor leaks around fittings but nothing serious. Once these are rectified, it is time to strip her down for painting.

We noticed that the side tanks on POEM were less than flat. This was a problem because I wanted to move the nameplates to the tanks. We got a panel-beater to have a look at it and after a few knocks with a hammer all is well. Apart from sorting out the rust on the tender, we're all ready to paint her (OK, a bit more complicated than that).

February 2009

 

All of the bodywork has been taken off and sent to the painters. We're not stripping her right down, so we'll have some touch-up work to do on the chassis, etc.

The trailer (for POEM) is also nearly finished, so within a few weeks we should have her out on some tracks.

The boiler barrel and domes are back from the paint shop and they look great. Also, the trailer is nearly finished. John Bremner reckons we should have POEM running in about a month.

It is a VERY small world. I got an email from someone I know in Croatia, who had read the newsletter of The Valley Model Engineering Society (don't ask me how or why!). In their February 2009 edition POEM and I get a mention.

The trailer is off to the galvaniser this week.

The cab and tender are back from the paint-shop. The green is a bit brighter than expected but it looks great. I am so glad I got it done by a professional rather than trying to do it myself. It'll b a push, but we might get her back together in time for Manu Ariki on the 7th/8th March.

March 2009

 

Everything is starting to come together now.

I am not sure why, but the green has come out somewhat brighter than I anticipated. I checked the colour samples carefully, but it is a bit "green". Anyway, It is not so bright that it is "bad", and it is growing no me. I guess I'll just have to wait for the Kermit jokes!

We've put the tender back together. The seat will need to be recovered as blue doesn't go with the new colour scheme, but this is a job we can sort out later.

 

This is John Bremner sorting out the plumbing to the vacuum brake valve. One sidetank is back on. Boiler cladding, domes, chimney all painted.

I am going to make the buffer-beam a shade or two darker. Not sure why both the green and red have come out brighter on the loco than on the colour samples; very odd.

 

After a lot of polishing, all of the brass and copper pipework is now nice and shiny. Not sure how long it'll stay that way mind you!

We need to fit the new gauges, but we may have to use the two old vacuum gauges just to get us running for Manu Ariki.

 

John Bremner made up a clover-leaf shaped bracket for the gauges and I mounted it all up - it look great.

 

John Bremner, Brett (a friend of John's) and myself almost pulled an all-nighter getting POEM and the trailer ready for the weekend - I got to bed a 2:15am.

We did a steam-test on POEM and everything was fine. The only thing we have left to do is to put the cab back on (about a dozen bolts), it was just easier to do the steam test with the cab off. There's still some jobs to be done later on, but 99% of the rebuild is now complete. JB also repainted the buffer-beam a darker shade of red - it looks much better now.


Here's a summary of the work we've done to her over the last 6 months:

  • Raised the sides of the footplate by 75mm
  • Trimmed the cab sides to match the raised footplate
  • Trimmed the cab roof so it doesn't hit your knees on corners
  • Moved the water valves and all associated pipe work
  • Made new water valve handles and fitted them to the cab sides
  • Modified the regulator so it works the "normal" way round
  • Fitted new steam and vacuum gauges
  • Lengthened the chimney
  • Moved the headlight
  • Rerouted or replaced all the pipe work - do not underestimate the effort involved!
  • Changed the cab handrails
  • Raised the chimney clear of the dome
  • Modified all the steam valve handles - we got tired of burning our fingers
  • Repainted (done professionally)
  • A friend made a tray to go in the ash pan to help in dropping the fire - for some reason Murray didn't design it so you could simply drop the fire (grate and all) out the bottom. Might have to fix that.

Jobs still to be done:

  • Connect up the new vacuum gauges - they are just sitting there looking pretty at the moment - we were in a hurry
  • Improve the way the tender water hoses are connected
  • Put the nameplates on the side-tanks
  • Re-upholster the seat so it matches the new colour-scheme
  • Connect up the headlight and fit cab and water level sight glass lamps
  • Paint the outside cranks red - only if I can do it without taking the valve gear apart

I can't wait to see people's reactions to her after the rebuild; JB and I both think she looks awesome. She didn't have a lot of "street cred" in blue and purple, but she looks like a totally different loco now.

 

POEM after her rebuild standing outside the loco shed at Manu Ariki

We took POEM to Manu Ariki and had a "mixed" day. After about three runs round we noticed that she was "fighting" against herself and after having to push her back to the shed we found that one of the keys had come loose on an eccentric causing the valve events to be all over the place. The annoying thing was that we didn't even touch the valvegear during the rebuild! It is all fixable, just annoying.

Until the key came loose she worked great, so that is good news. JB reckons we should be able to sort that eccentric out tomorrow at our weekly workshop evening and hopefully be at Hamilton next weekend.

 

JB and I had a look at POEM's valvegear. A key on the back of one of the cranks had come loose and appeared to be the cause of the problem. There was not a huge amount of play in the valvegear, but when I had trouble at the weekend I found that pushing the reversing lever as far forward as it would go made a noticeable difference. The play or slop in the valvegear caused by the loose key was about five times as much as the movement due to pushing the reverser hard forward, so it is quite likely the cause of the problem.

I also noticed that in full forward gear the radius rod was not in-line with the lower eccentric rod. This means that the loco is effectively running with no more than about 50% cutoff, or not being able to utilise full power. It turns out that the slot in the footplate where the reversing lever goes through wasn't quite long enough. We made a few adjustments and it is a lot better, but if this doesn't solve the problem I'll need to modify the reverser slightly to get more throw in forward-gear.

But, she's running on air fine and we'll be at Hamilton at the weekend.

 

Running weekend at Hamilton

POEM misbehaved again. The hydrostatic lubricator doesn't seem to be working very well and as such the lubrication isn't getting to the cylinders. This could be the root cause of some of our problems.

We'll get these things fixed but it is annoying.

 

Workshop update

John Bremner and I put the reversing quadrant back the way it was before we rebuilt it all (not that big a job actually) and measured up the movement in the expansion link. We then put it back as it was post-modifications and measured it all again. It looks like we had slightly too little movement in forward gear to get the full valve events. It was so small we never even gave it another thought but it might be enough to explain a few things. We just need to test POEM under steam now. As we are moving house this will not be for a few weeks yet but we are optimistic.

   

May 2009

 

Another workshop update

John and I put everything back together and measured the valve travel as per Murray's original drawings and we're now ready for a steam test.

There is a definite design fault in the return cranks. With the outer crank fixed to the inner crank the load on the inner ones is effectively doubled. As it stands the cranks are a bit small for the job and over a period of time the inner one comes loose. We can tighten up the grub screws but they will come loose again. I am seriously considering making new, larger cranks - which should overcome the problem.

POEM will definitely be going to Grant Alexander's mid-winter steam up, though she'll probably be running without the cab on as it is easier for us to get to the bits we've modified.

Oh, and we piped up the new vacuum gauges too.

June 2009

 

Grant Alexander's Mid-Winter steam-up

After we got off to a bit of a shaky start (derailment coming off the trailer), POEM ran well all afternoon. For some bizarre reason the vacuum brakes are sticking on (something else we didn't actually touch during the rebuild) and the lubricator is still causing grief - we think we'll put a mechanical one on there instead!

Other than that, it was a great day, and the weather held off too.

July 2009

 

The lubricator is now working fine - we suspect there was a blockage somewhere. Now all we need to do is sort out the brakes.

August 2009

 

John Bremner took POEM down to the Hamilton club track over the weekend and she ran well all day. The brakes are still a bit lame so we'll look at why and do some rework, but otherwise she's running well.

Mike Orange from the Manukau club suggested that one of the problems with POEM's valvegear is that the steam ports are too wide; he apparently saw POEM being built and wondered at the time. Because the vales themselves are so big there is a lot of load on them (steam pressure x surface area = a lot) and this is putting a lot of strain on the valvegear. He suggested that the ports could be halved in size and still work well.

It'd be a simple enough job to make two new valve plates and two new valves to try them - and if it didn't work, change them back again. This is a job for when things get a bit quieter in "my life outside trains".

September 2009

 

Pip and I went back to the UK for the month, so no activity on POEM.

October 2009

 

John Bremner found the recurring problem with the left-side crank has not been resolved so we decided not to take her to Havelock North as we didn't know what might happen over a weekend of continuous running. I (we) will now concentrate on fixing the problem once and for all.

March 2010

  I have decided that the best way to resolve the recurring valvegear problem is a staged approach:
  1. Replace the two cranks on either side with new ones of larger proportions - this should stop their current tendency to work loose over time.
  2. More drastic action.

I prefer option (1) for now!

Unfortunately, I am really busy getting our business off the ground and I cannot spend as much time as I'd like working on POEM.

  Due to work commitments we're not making much progress. I was out of the Waikato for six weeks over June and July. Oh well, there'll be time when things quiet down a bit.
 
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