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A Large Scale Bagnall

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I have acquired a large scale Bagnall Sipat. When I say large scale I mean 7.25 inch gauge, 5 inch to the foot scale, live steam and approximately a quarter of a ton. 


46598344575_25bd377230_c.jpg20190330_155714 by 47845, on Flickr


The loco was built in 1989 to a design by MJ Engineering and serialised in Engineering in miniature. I believe this was one of the first to be completed to this design and the loco sees very little deviation from the drawings. The engine was run around the north west of England for about 10 years until 2000 when its boiler was retubed (more of this later). it was used until (officially) 2003 when its most recent boiler ticket expired, whether it has been steamed in the meantime is pure speculation as the previous owner was not around to ask. For an engine with 15 years of storage under its belt I felt it was in incredibly good condition, nothing more than a light surface rust on some of the motion, nothing was seized and it made all the right noises when being hand shunted about meaning the steam circuit was still tight. 


I bought the engine with my eyes open. obviously storing a loco for so long in unknown conditions could take its toll, and there was the case of the last retube to consider. In 2000 the then owner felt it appropriate to install stainless steel tubes in place of the more standard steel or copper. The loco was inspected and passed consecutive years after this with apparently stainless steel tubes fitted even though it was always my understanding that stainless was a no-go in live steam. 'How could his club have certified it?' I wondered... 'It must be a mistake'.


Speaking to my boiler inspector we concluded that everyone would be happiest if, prior to recertification, the boiler could be examined 'naked' and out of the frames. This would also give me chance to go over all the hard to reach places and investigate the stainless tubes better. work started immediately


46873696834_0f317bd7b4_c.jpg20190409_194710 by 47845, on Flickr


I was working in a bit of a mess since I collected the loco as the garage had been accumulating all manner of wares to do a car boot sale (the fall out from re-decorating the house), The car boot came and went on Sunday giving me opportunity to clear some sort of work space. Just need to sell the bogie coach now as it too is in the way!  The locos you can see in the picture below are obviously the Sipat taking centre stage. The small 5 inch gauge yellow diesel is in fact a Maxitrack battery electric 'Planet' sat on top of its driving truck and the loco on the bench is my 7.25 gauge Jessie which is awaiting its new owner coming to collect it. As you can see the boiler has now parted company with the frames. the steam raising blower can bee seen on top of the chimney also. 


33735837348_901a7bbda0_c.jpg20190415_080017 by 47845, on Flickr


The chassis has been cleaned a bit to get some of the 15 year old oil off. the brightwork will be cleaned up next and any paint touching up will happen soon so I can re-oil and protect everything on the bottom end. So far no shockers, everything adds up to show a very well made engine in the first place. 


46697462925_426f60d4f2_c.jpg20190415_080029 by 47845, on Flickr


The boiler took a little more persuasion to get off. The inside is a bit nasty but that was to be expected. I have cycled some descaler through the boiler a couple of times to break up some of the crap and flushed it clear. on Saturday I took it to the local garage to pressure wash it from every angle and in every opening. It now runs clear. I have my concerns about the inner firebox but I am having it ultrasonically tested for plate thickness on Sunday. This will determine its fate as to whether a new one is required or not.


47613082231_47ebd2e093_c.jpg20190415_080034 by 47845, on Flickr


Back to the saga of the tubes, it turns out they re in fact stainless. I have heard conflicting reports about their suitability ranging from 'they are fine, leave them be' to 'take them out it is illegal' and most things in between. I will not be making any rash decisions until the thickness test is complete but currently the options are:

Thickness test fails - new boiler required

Thickness test fails on firebox - possibly new firebox or boiler

Thickness test passes - replace tubes for steel or copper

Thickness test passes - test code rewritten and stainless tubes are accepted!


46873697504_101b2b0177_c.jpg20190412_131432 by 47845, on Flickr


Its a seemingly long wait until Sunday now!


Edited by 47845
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  • 2 weeks later...

The overhaul is progressing slowly at the moment. 


46936655374_2e2babc854_c.jpg20190421_120840 by 47845, on Flickr


I took the boiler to see my inspectors on Sunday and they said they would like to see it 'acid dipped' to remove all trace of rust and scale from the plates inside. This could potentially delay things and first I have to get the 32 old tubes out (not a simple task I must add) and find a reputable pace to 'dip' the boiler shell. This is so the inspectors can fully assess the levels of pitting in the crown of the firebox. The inspectors are currently unsure how thick the plates are due to the build up on them as such they couldn't advise if its either a scrap boiler or whether I can squeeze one last ticket out of it. The crown (the bit directly above the fire) is one of the most susceptible parts of the boiler to corrosion due to being exposed to the most heat. mine currently looks like this....


47660715201_9ab6326807_c.jpg20190421_185445 by 47845, on Flickr


As the boiler is being worked on separately my attention has turned to other parts of the loco so that it is ready to accept the boiler back when its done. this will speed up the re-assembly considerably  as everything *should* fit straight back on where it came off and will be cleaned and steam tight. One of the clack valves can be seen below, this is a simple non-return valve for water to be fed in to the boiler. the feed passes up, lifting the ball off its seat which is then re-seated by boiler pressure when the flow stops. This will now be stored 'clean' ready to go back on the loco when the time comes. 


47660714811_46317f6fa3_c.jpg20190415_193012 by 47845, on Flickr


More to follow if and when things progress!



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  • 3 weeks later...

Well after a modest battle over a week I have managed to get all of the tubes out. Image below shows the inside of the boiler barrel water space with just a couple of tubes left to come out. it can be seen how much 'loose scale' is in the bottom of the barrel. this has all come of the outside of the tubes and been scraped off the surface as the tubes were withdrawn from the boiler. 

47743109072_5deedd4167_c.jpg20190504_190014 by 47845, on Flickr

The tubes are expanded in which means they are fatter at each end to make the seal with the tubeplate. when hammering out a tube its difficult to break the initial seal but when you get to the standard with dube you are only battling against the scale. what is difficult however is getting the tube out past the other 'fat bit' on the other end. the way around this is to draw the tube out by a certain distance, hacksaw off the 'fat bit' and push the tube back in to the boiler thus dropping between the tube plates at each end. the dropped tube can then be withdrawn through the larger diameter washout hole on the end. the various lengths of removed tubes are seen below as a result of this exercise

40829091783_f6855f7c0c_c.jpg20190505_165624 by 47845, on Flickr

With all the tubes out my boiler inspector is happy to pass the boiler to be retubed although due to its age he has granted me a ticket on a shorter inspection cycle of every year instead of every 2 years. with this in mind I have now ordered the tubes and will commence the retube as soon as they are delivered.

32851934237_f3146e1183_c.jpg20190505_165807 by 47845, on Flickr

Whilst I was cleaning up other areas of the loco I noticed what looked like a flake of paint behind the cylinder end cap. closer inspection revealed this to actually be the gasket from said cylinder that had blown clean out. Time for unexpected job number 2. I spent the evening stripping down the valve gear on both sides to gain access to the cylinders so I could replace the gaskets for both front and back caps both sides. better to do all at once than have to revisit it at a later date. I took this opportunity to withdraw the piston completely from the bore for inspection. Once I have some suitable gasket paper this will be put back together. 

32874340017_dcb01da3e1_c.jpg2019-05-10_02-54-55 by 47845, on Flickr

The club open day and the locos potential first steaming are now 3 weeks away. nothing like a deadline to focus the mind!


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The boiler tubes are now ordered and will be delivered on Thursday from TSS in South Wales. Luckily there are plenty of other jobs to be cracking on with. I spent Saturday PM refitting the regulator and main steam pipe as can be seen in the attached two photos, both open and closed. 


46924813745_e53a07ccd1_c.jpg20190511_191728 by 47845, on Flickr

33963740318_cf4e31d325_c.jpg20190511_191732 by 47845, on Flickr

I also took this opportunity to refit the gauge g lass fittings (no glass fitted yet so I don't damage it) and washout plugs (the latter at least until the tubes are fitted and it has a final wash out )  


32897151807_348c4e38d3_c.jpg20190512_150722 by 47845, on Flickr

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its getting close... Well the new tubes turned up on time on Thursday. A quick count and measure to make sure all was well meant that work could begin on the big job!


46968520035_faca7e512e_c.jpg20190517_181349 by 47845, on Flickr


The first task was to anneal the tube ends. This heating (to a dull red) and (slow) cooling cycle changes the structure of the steel and allows it to be 'expanded' in to the tube plates easier.


46968519925_39764c8680_c.jpg20190517_182814 by 47845, on Flickr


With all the ends treated it was time to start fitting the tubes. Each tube was placed in its respective holes and expanded, starting from the outside working in a spiral fashion. The process was slow to start with but once I got in the rhythm its wasn't as bad as I had expected. All tubes were in by late afternoon Saturday. 


46968519755_7f63c39e4b_c.jpg20190518_145153 by 47845, on Flickr


 One to go!


47095281404_18b7436bd2_c.jpg20190518_153840 by 47845, on Flickr


I had a bit of spare time at the end of the day so filled the boiler up with water, fitted the test blanks and had a go at putting some pressure on it. 50psi at first and few tubes were weeping at the firebox end. The problem areas were fettled and tried again, 100psi this time and both tube plates were dry. A bit more pressure, 150psi but the clack valves and water gauges started leaking a little - no problem, the tubes were holding at least - 180psi and the same, tubes were fine but due to other 'weeps' the pressure was not holding. 


47884596881_0c38ba0ab2_c.jpg20190518_175901 by 47845, on Flickr


Sunday evening I decided to put the boiler back in the frames. the small niggly weeps will be sorted as the rebuild progresses. The smokebox was refitted and sealed and the cylinders had new gaskets cut and refitted which allowed me to rebuild the valve gear


47095282554_acd549ae00_c.jpg20190519_192419 by 47845, on Flickr


Starting to look like an engine again. Tonight's job is to get the tank back on and the plumbing back together. The cab will only be loosely fitted at this time until I have put a fire in and tested the loco under steam. Fingers crossed nothing else raises its head!

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After sitting dormant in a shed for 17 years, a 2 month fast-track overhaul and a bucket full of midnight oil, Late afternoon on Wednesday this happened...


46995383885_4b1215d129_c.jpg20190522_172901 by 47845, on Flickr


Shortly followed by this....



It held steam and was dry at all the joints, so I slowly raised the pressure up to full working pressure (90psi) to set the safety valves. The are fine if a little slow at reducing the pressure, I shall put some new ones on the 'snag list' for now...


47121996504_c4d2059896_c.jpg20190522_183241 by 47845, on Flickr


With a good head of steam and about 15 foot of track extending out of the garage I couldn't resist seeing what it sounded like! It was priming quite badly but this will settle after a few washouts, this is due to residue in the boiler following the overhaul



and finally cooling down after a successful trial...


47121996434_2b4a3a167c_k.jpg20190522_185209 by 47845, on Flickr

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  • 2 weeks later...

What a rollercoaster of a week! I had planned to take the loco to the track last weekend to try it out before the event and still give me a week to fettle anything arising from the test but sadly it wasn’t to be. I had to wait until last Friday to get it to the track and hope everything went well! Another item of note I had 'Midland Loco Works' make me a new pair of nameplates which I had fitted on the Wednesday in readiness for the first outing...


47993212328_76cac3b4c1_k.jpg20190529_203614 by Steve Purves, on Flickr



Arrived at the track around 2pm, unloaded and got the loco in to place on the steaming bay for our boiler inspectors to conduct a 2x working pressure (180psi) hydraulic test to ensure the boiler was safe to operate at its normal 90psi. This test was passed with flying colours.

Now it was time to light a fire… This was the bit I was most nervous about, as from the test steaming on my drive I noted that the safety valves fitted were a bit naff but ran out of time to get them replaced. Part of the steam test is called the accumulation test. This involves having a good hot fire with the blower hard on to make as much steam as possible, the safety valves must lift and not allow pressure to rise over 10% more than the working pressure (99psi in my case). We stood back and watched the needle climb and climb up past 100, on to 110 and still going. This was no good! We allowed the boiler to cool and reduced the pressure back below the red mark. Test Failed. There was no way that the safety valves as fitted were fit for the job, they just couldn’t clear steam fast enough – certainly not as fast as the Bagnall boiler could make it. Time for a rethink. The valves operating pressure was backed off to 75psi, this meant that when they opened at 75psi and kept climbing they would stop climbing under the magic 99psi (WP + 10%) Again test failed, this time though it climbed to about 105psi. There was just time for a third retest, this time the valves would lift at 65psi. Success!


47993210413_034e9e61d4_k.jpg20190531_161600 by Steve Purves, on Flickr


Time allowed for half an hour of track time before retiring for the night. This quick ‘road test’ went extremely well and highlighted no concerns for the following morning. The loco was to live in the carriage shed for the weekend so the fire was raked through, injector put on to fill the boiler and left to cool overnight…


47991528183_f78d289bd3_k.jpg20190601_164209 by Steve Purves, on Flickr



The show opened at 10am which meant I should be ready to light the fire for about 9am to give me time to raise steam nice and slowly, oil round, polish, get the coaches out and be sat in the platform at ‘go’ time. The full boiler the night before had settled to around a quarter of a glass by the time it cooled so no top up required before lighting up. Everything went well, I pulled the empty stock in to the platform for 10:01 which was more luck than judgement! 

Saturday was a hot day, it was a busy show and no sooner had my passengers disembarked than the next load had jumped on. Each ride was 2 laps of our circuit so about 3 to 4 minutes in total, I shared the passenger hauling with a nice Royal Scot and we had one passenger car each (about 4 adults). Because the loading was light I didn’t need to run the engine above around 50psi all weekend. I did notice that the right cylinder was running warm and was a little dry of oil so I made a note to keep an eye on this, it did settle down over the course of the day. 




 47991584101_3d00b705fe_h.jpgIMG-20190601-WA0003 by Steve Purves, on Flickr


I finally retired at 17:00 after running the engine continuously for 7 hours… I even forgot to stop for lunch! Not bad for its first run in about 16 years! The engine was given a quick polish, and the process repeated for the second night before it was bedded down in the carriage shed again. 



The weather forecast was not so great for Sunday and also less than 5 miles away we had the ‘Rutland Show’ to compete with. Again I was on the track at 10am ready to start the day. Today I ran the first hour alone before I was joined by a nice Quarry Hunslet. It got quieter after lunchtime and we suffered a couple of showers. The hunslet came off about 14:00 whilst I carried on until 15:30 when a Class 25 took my place for the last hour.


47991574576_c38cac9eb7_k.jpg20190602_144001 by Steve Purves, on Flickr


This time the fire was dropped on the steaming bays as the loco had to be loaded back in to my trailer to come home with me. The same procedure was followed with the fire coming out and the injector filling the boiler right up. The loco was loaded and put back in the garage until next time.


 47991525568_4cd057eec7_k.jpg20190602_152540 by Steve Purves, on Flickr


In summary, What a weekend! I couldn’t have asked for more of the engine. It ran all weekend on just a whisp of steam and performed faultlessly. There is a gallery of images from the show here : https://flic.kr/s/aHsmDZhcTx


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  • 1 month later...

Well that was fun!

Thanks to the Rugby Society of Model engineers for welcoming us to their 'Rainsbrook Valley Railway' over the weekend for their Narrow Gauge Gala. A superb track with first class facilities and a very warm welcome. I shall be returning!

The track had recently been extended to a mile in length with a daunting climb of 1 in 100 to make the engine work, I won't go in to too much detail but let the pictures speak for themselves. 

The first two images show the new 'top' station which I believe will be formally opened this coming weekend along with some of the locos on show


48296353627_dbceb5dbbe_h.jpg20190714_134334 by Steve Purves, on Flickr


I was given a 3 coach 'Pullman' rake complete with carpeted floors and leather seats!


48296353172_7291de4b5a_h.jpg20190714_134351 by Steve Purves, on Flickr


This loco deserved a photo. Sorry I didn't get any details but what a stunner!


48296352247_56b9349205_h.jpg20190714_141455(0) by Steve Purves, on Flickr


A picture of my loco in the cutting at the 'bottom' of the line. I really need a more prototypical driving truck!


48296352372_2c6aec2263_h.jpg20190714_152627 by Steve Purves, on Flickr


And finally a couple of videos for your enjoyment...

A full lap on board


and another video showing the length of the 1 in 100 climb


Until next time....

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  • 1 month later...

Well the big news is that we have turned our hobby in to a business...


Yesterday we launched the "There and Back Light Railway Company'. We are using the winter to build 200 foot of portable track and take our engine and coach on the road. We will be available for all kinds of events both public and private! 


Give us a look...




or There & Back Light Railway on Facebook!

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