November 2019 – News Letter

Preamble

I’d planned to have something out in October, a respectable three months on from the previous issue, but life has an irritating habit of getting in the way of things. As Edmund Blackadder so eloquently put it – “The path of my life is strewn with cowpats from the Devil’s own Satanic herd”. Be assured, however, that I’ve swept up and what follows is wholly fragrant ….

Around and About the Club

Big things have been happening out on the grass of late as work has progressed steadily with building the new Carriage Shed for the raised-track riding trucks. Many cubic metres of soil have been excavated to prepare the ground for the floor-slab (6m long by 2m wide by 10cm deep) which sits several centimetres below the surrounding ground level. Four courses of blockwork are raised on this to roof-eaves level. A door-frame and sill have been fabricated in steel which occupy the full width of the track-ward end. Provision is made in the floor to bring in mains electricity.

Whilst the ground works for the carriage shed were underway, the area in front of the locomotive shed was also prepared to accommodate the new dual-gauge traverser and the slab for this was poured at the same time.

Work also continues with improvements to the track signalling and point control systems. Receiving attention now are the points between the station loop and main line so that these cannot be operated whilst a train is in transit. Additional train-detectors have been installed in the track and associated cables laid-in back to the Signal Box where a new cabinet houses the extra circuitry required.

Creosote Day, Saturday 7^th September, witnessed a good turnout of willing helpers to get this annual maintenance job done. Both ground-level and raised tracks were thoroughly treated using a combination of spray-guns and brushes.

If you’ve visited the TSMEE website recently, you’ll have noticed a quite radical change in appearance and content. John Rowley has taken over the job of webmaster and is keen to stress that it is, presently, very much “work in progress”. User feedback and constructive comments are welcomed.

Events …

Open Weekend 27^/28^th July

This annual two-day event was not blessed with particularly good weather. It rained on-and-off on the Saturday and Sunday was dry but overcast. Nevertheless, there was a respectable turnout of both TSMEE members and visitors, the latter hailing from as far afield as Scotland, Cumbria, York and Leeds.

Visiting locomotives were :– in 3-1/2” gauge  BR “Britannia” 4-6-2, Great Central O4 2-8-0, Freelance 4-8-2 – in 5” gauge  “Chub” 0-4-0 Tank, BR Standard 4 2-6-4 Tank, NER Q6 0-8-0, NER B2 4-6-0 – and in 7-1/4” gauge  GWR 14XX 0-4-2 Tank .

Saturday lunch was Fish ‘n Chips and on Sunday our Catering Stalwarts laid on their usual splendid buffet.

Trip down the Tyne 31^st August 2019

Six members joined our party on the “Fortuna” for a cruise down to Tynemouth from the Quayside in Newcastle. The weather was reasonable, even allowing for the blustery wind, and we all enjoyed the trip.

There is a full and very informative commentary on the way to Tynemouth. I have made the trip a couple of times over the years and I am amazed by the way that Tyneside industrial heritage has disappeared in a comparatively short time. It used to be the remains of ship yards, dry docks and associated industries all the way to Tynemouth. Now much of the bank-side is wooded and under modern housing. It all looks very different.

The remaining working areas are impressive and Tyne Dock is massive. The Fish Quay and Tynemouth with the Harbour Lights, like much else of the riverside, are becoming tourist attractions. That’s progress, so we all went to the bar and drank to the past.   Malcolm Phillips

Trip to see the G5 at Shildon and the P2 under construction at Darlington, 7th October 2019.

Another enjoyable day out, perhaps more related to model engineering. Volunteers at both sites were very helpful and thanks are due to Phil Work who kindly arranged tea and biscuits at Shildon.

The G5 is not quite an engine yet, but most of the parts are ready to go together. The frames, boiler, cab and plate-work just need finishing touches. The bogie for the 0-4-4 and one set of driving wheels have been finished but the crank axle has yet to arrive, as manufacture of parts and machining is all done outside. The group has been working to original plans and has had to make many patterns, some of which are placed beside the finished castings.

From Shildon we proceeded to Darlington. The P2, to be named “Prince of Wales”, is a truly impressive machine. Like the G5 it has yet to go onto its wheels, all of which have had their tyres polished to a mirror finish.  Cab and smokebox are on the frames and the boiler cladding is set up on frames beside the locomotive as the boiler is yet to come from Meiningen.

We were told about some of the technical problems – the wheel flanges have been computer designed to ease passage round curves on Heritage Railways and steam distribution will be by poppet valves.

The original Gresley design was not too successful so the designers have used the designs evolved in America after the war which were better. Boiler design has been modified by experience with Tornado and their boilers are interchangeable.

I do not know what will become of the polished wheels – one of the volunteers told me that the painters were upset because on its first trip to York of thirty miles, their beautiful paint finish was spoiled by excess grease and oil coming out of the axle boxes!

The NELPG shops were closed so we completed the trip with a visit to the Head of Steam Museum across the way from the Hopetown works. This is a nice museum with exhibits of Stockton and Darlington and NER origin. Hackworth’s “Derwent” and “Locomotion” are well displayed and there are some interesting small exhibits.   Malcolm Phillips

For your diary …

Public Running Day – Santa Special – Sunday 1^st December

Christmas Tea – Sunday 22^nd December

Something a bit different now – Gordon Bullard has very kindly submitted the following rather interesting article…

An Automatic Cylinder Drain-cock

Back in the 1980’s over a pie and a pint in a local hostelry, a friend and I were discussing the pros and cons of cylinder drain cocks and associated linkage to the cab of a miniature steam locomotive. 

The locomotive he was building had two sets of Stephenson’s valve gear and an axle pump between the frames, together with lubricator linkage which left little room for direct drain- cock rodding.   We discussed the possibility of automatic drain cocks and I suggested that a small inverted safety valve type of arrangement might be possible.

A set of small valves was made and fitted, each consisting of a stainless ball which was held on its seat by a small bronze spring.  The valves performed well but they looked like upside-down safety valves, which is, of course, exactly what they were.

Clearly, a horizontal arrangement was required which would be more prototypical of full sized practice. So, another set of valves was made in a tee configuration with basically the same internal arrangement but in a horizontal orientation.

These valves worked reasonably well. They certainly cleared the cylinder condensate very efficiently but for some reason when the locomotive was running slight puffs of steam were occasionally noticeable. 

Closer observation showed that one of the valves seemed to be working well with no visible leakage whilst the loco was running.  With the expectation that the poor sealing of the three sub standard valves was probable due to poor workmanship on my part,  all of the valves were disassembled for examination.

I was amazed to find that I had forgotten to put a spring in the valve that worked perfectly.  The valves were quickly reassembled without springs and found to all work perfectly.  Since then I have fitted this type of valve onto three of my locomotives with no failures.  The last loco was to LBSC’s “Maisie” design and has run on the club track on numerous occasions.  The attached drawing shows the design of the valve which is made of bar material with a silver-soldered joint.

 It took a while to work out how the valve worked without a spring.  When the locomotive is stationary any condensation in the cylinder drains down into the valve where the ball is resting on the bottom of the chamber so any water can drain away via the front hole. 

When the regulator is opened a combination of condensate and steam enters the valve where the ball is unable to seat properly due to the turbulence in the chamber.  A combination of water and steam exits the valve due to this turbulence until all of the water is displaced, which leaves the chamber full of steam which in turn forces the ball onto its seat.  It’s as simple as that.

You may well ask what the reduced diameter on the rear of the valve is for.  It is purely there to improve the fitting visually, disguising the fact that it is just a piece of simple bar material.  For members who follow full size practice and require drain piping to the locomotive’s buffer beam,  the front of the valve seat could have a small ME thread machined onto it to take a nut, nipple and associated pipe.

In conclusion, this simple valve is easy to produce, is fully automatic in operation and requires no linkage to the cab.  It would be easy to say that I had a light bulb type of moment concerning this valve’s conception but in reality it came about more by accident than design.

Postamble

As I remarked in the previous issue, a Newsletter requires News, and this one would have been a rather thin affair but for the contributions of Malcolm Phillips and Gordon Bullard. My thanks to them both.

Membership Subscriptions will be due for renewal at the end of the year. The cost remains at £35 Single and £45 Family. Our Treasurer Ian Spencer will take payment in cash or cheques (payable to “TSMEE Ltd”).

The three holes are for the two location dowels and the bore centre

The part is mounted in the four jaw and bored to fit the valve chest. After facing the part is remounted on a fixture and set up on the rotary table to be counterbored off centre with a radius at the base forming the cavity around the valve chest.

Milling operations complete the passageway, with a ball nose cutter to finish the internal corners.

The cylinder face is milled while still on the rotary table

The outside edge is then milled to radius

The sides are also milled to size and the part turned over to radius the outer edge with a corner rounding cutter

Machining complete on all eight steam passages

They were heated and split

A pair are in place on a cylinder but not fixed

Gresley designed cylinders had a cast in back cover so the next components to make were these. They are a simple turning exercise and have a spigot on the cylinder side to locate, with a thin flange on the outer face to make them appear flush with the cylinder back when dressed off.

Components are temporarily fixed using 10 ba studs. The parts are clamped together and tapping size holes drilled as necessary, tapped and the stud screwed in. This is normally sufficient to keep things together till silver soldered. Two of the back covers in place

Now at the point where the cylinder could have its first stage of silver soldering. All areas that would be better if they were not coated in solder were painted with correcting fluid (Tippex in this case)

The joints were then treated to a generous coating of flux, in this case HT5 because I fancied the operation might take some time.

Also - The joints were then treated to a generous coating of flux, in this case HT5 because I fancied the operation might take some time.

Here's a cylinder set up on the hearth for the first stage

The silver soldered cylinders were cleaned up in a pickle of citric acid and because the soldering operation was difficult with areas that were not in direct sight it was essential to hydraulic pressure test to ensure there were no gaps in the joints. Figure 16 shows the hydraulic test set up. The arrow identifies the position of a leak to be rectified on the next heat up.

Cut outs were made in the cylinder end plates to make way for the exhaust passages from the ends of the valve chest to the already machined openings in the back plate. The sides of these were angled as required using the Dremel and files.

Also - Cut outs were made in the cylinder end plates to make way for the exhaust passages from the ends of the valve chest to the already machined openings in the back plate. The sides of these were angled as required using the Dremel and files.

2mm brass sheet was machined to make a pair of side plates to neatly fit the valve chest flange.

After splitting these were shaped and bent to make the outer side walls of the passages.

Inner plates were made up similarly and fitted and stiffeners were made and fitted fitted as the prototype. The S shaped passage bases were labouriously cut, filed and bent to shape and clamped in position before inserting the 10 BA fixings.

An open cylinder end, masked, fluxed and ready to solder. Then on the hearth being silver soldered.

Also - An open cylinder end, masked, fluxed and ready to solder. Then on the hearth being silver soldered.

Once all the fronts were done the brackets for mounting the slidebars were needed so they could be silver soldered at the same heating as the backs. The cylinders were mounted vertically on the mill and two holes were drilled to locate the brackets.

The brackets were machined from phosphor bronze with two 10 BA tapped holes in the back Figure 25 shows all six complete with fixing holes for the top slidebar and for the side support ready to be fitted.

The components for the slidebar bracket

A cylinder rear with the slidebar support assembled.

At this point I needed to start machining the partly built cylinders so the next parts to be fitted were in the correct positions. After careful measurement of the relationship between the cylinder and valve bores listed here

I made a setting tool that could be clamped to the cylinder to use to orientate them correctly for further machining and using the mandrel previously made for machining and testing the cylinders, they were set up on the rotary table. The setting tool was clamped to the cylinder and used with the dial gauge to ensure the bores were correctly positioned.

Also - the setting tool was clamped to the cylinder and used with the dial gauge to ensure the bores were correctly positioned.

A reference face was machined to be used for future set ups

At the same set up a 3/16" end mill was used to plunge mill the recesses for the lagging fixings around the inside of the end plates.

Brass inserts were made and drilled for tapping 10 BA and fixed, each secured by a 10 BA stud through the side.

The tops of the exhaust passages were fitted ready for the next silver soldering operation. Each passage was traced on to paper, cut out and glued to 2mm sheet brass, a process already used but not photographed for the floors of the passages. Care was taken to keep the gaps small as the silver solder would need to bridge these.

Next the seats for the cylinder drain cock flanges were drilled part depth and counter bored.

Pieces of bronze were machined to the correct radius for the cylinders and drilled for the cylinder drain passage and the drain cock fixing studs.

Also - pieces of bronze were machined to the correct radius for the cylinders and drilled for the cylinder drain passage and the drain cock fixing studs.

Cut into sets of 4 these were profiled in the milling machine to produce the flanges for the drains.

Also - cut into sets of 4 these were profiled in the milling machine to produce the flanges for the drains.

Also - cut into sets of 4 these were profiled in the milling machine to produce the flanges for the drains.

These were attached by the usual method.

The main steam inlets were bored next. As they enter with a considerable off set on the steam chest they were set up in the milling machine and bored with a centre cutting end mill.

The inlet flanges were made now and turned up from in bronze.

They were then screwed onto a mandrel and the boring head was used to create the matching profile to the steam chest.

To locate them on the steam chests a brass stud was screwed into the inlet and finally secured with a blind nut and a couple of 8 BA studs for security. Note also the brass bar fitted along the top of the cylinder for fixing the footplate angle.

The cylinder was then masked and fluxed ready for the final silver soldering operation.

After the soldering the cylinder looks a bit of a mess before being pickled.

Following the clean up the cylinders were hydraulically tested to 200psi to ensure they were mechanically sound.

The middle cylinders were now on the programme, and planning ahead it could be seen that the smokeboxes would be needed soon to help with making the smokebox saddle, which on the Gresley pony truck engines is integral with the middle cylinder. After searching for suitable steel tubing and discovering that I could get thick walled imperial cheaper than thinner walled metric, two pieces of 7 inch OD tube were obtained. These had 3/8" wall thickness so there was a lot of material to be removed to get the 9/32" wall thickness needed and I wasn't sure how long that would take on the Super 7, if indeed it could do the job anyway. Good friend Allan Bones came to my rescue with the offer of the use of his 6" Harrison. I last used one of these lathes when I was at school, where we had two brand new machines. Whilst Allan's machine has clearly been well used, it proved well capable of machining the smokeboxes to a high standard of finish and accuracy. The following photographs show the process of machining, taking a few afternoons over a three weeks period. Machining the outside. Note Allan's extractor duct to get rid of the smoke from the cutting oil.

Smokebox outside finished.

Starting the bore.

Bored as far as the short tool can go.

Deepening the bore with a longer tool.

Smokebox reversed to complete the bore.

Bore completed.

One down and one to start.

Rather than show you a picture of an engine with the smokebox in place on my untidy bench, I thought this photograph, taken at the Main Line Rally at Gilling, was more interesting. The K3 is seen standing next to Geoff Moore's award winning 2-8-2 of LNER Class P1 No 2393. If my locos are just half as good as Geoff's mikado, I will be well pleased.

Contact info …

Newsletter Editor – Mike Maguire ~ mike.maguire@btinternet.com

Club Secretary – Linda Nicholls – lindanic@sky.com ~ 01 670 816072

Website – John Rowley – webmaster@tsmee.co.uk ~ 07970 164 967

For your information – a PDF copy of this News Letter can be downloaded here ….