November 2019 - News Letter - Tyneside Society of Model & Experimental Engineers

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.

**Drain-cocks fitted to 3-1/2″ “Maisie”**

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 process begins in the obvious way with the preparation and machining of the end plates

Two cylinder back plates mounted on the mill for sizing and squaring

The steam passages were machined next from a block of gunmetal. Mounted on the rotary table the outside shape was simple to machine after drilling pilot holes for the centre of the steam chest and the outer radius and the holes for the mounting pins.

The top edge was finished using a corner rounding cutter

The piece was cut off using a hacksaw rather than setting up for a slitting saw.

The pieces were set up in the four jaw and after centering on the steam passage pilot , faced off and bored part depth to form the steam passage.

Once all were done, they were each put back in the mill to open out the steam passage for the connection to the cylinder

Also - Once all were done, they were each put back in the mill to open out the steam passage for the connection to the cylinder

The parts were then attached to the front and back plates by lightly riveting them using brazing rod

Followed by silver soldering

The front and back plates were then set up in the lathe for boring out the holes for the cylinders

Also - The front and back plates set up in the lathe for boring out the holes for the cylinders

As the valve chests are not parallel with the cylinders a different technique was required for boring the holes in the endplates.

The plates were set up on an angle plate on the rotary table on the mill. Slightly precarious, hence the blocks on the edge to stabilize the workpiece, and carefully bored to the require size.

Here they are temporarily mounted in the frames to show where they go.

Two side plates are needed to fix the inside cylinder to the outside cylinders. There are no bolts connecting the inside cylinder to the frame plates. the three cylinders can be bolted together to form a complete cylinder block, the traction forces being transmitted to the frames through the cylinder bolts and via the cut outs in the frame plates that closely fit the inside cylinder side plates. The side plate bolt holes are being drilled

The drawing for the side plates.

Milling the outside profile if the side plates using MNC (manual numerical control)

Slotting a side plate for locating the back and front plates and the longitudinal support

Slotting for the two internal support plates

Two side plates slotted ready for trial assembly

Unlike to outside cylinders there are no ribs on the inside cylinder barrel, seen here being bored.

The bore is opened up at each end and the internal chamfer made as the outside cylinders and set up with the end plugs so the outside can be turned between centres, concentric with the bore.

The outside is finished by rebating the ends, and reducing the middle to give the required wall thickness and then put on the rotary table to machine the locating slot for the longitudinal support.

With the same set up the steam passages are milled into the cylinder wall

An inside cylinder begins to take shape

The internal support plates are machined as the end plates but the valve opening is square to the plate and can be bored in the lathe. The valve bore is big enough to cut out at the side and a sacrificial piece of brass plate is provided so the tool does not collide with the adjacent chuck jaw.

The cylinder opening needs to be bored as before on the milling machine at the correct angle and here the holes are being drilled for the assembly rods before the main bore is started

The cylinder opening is bored to size

A trial assembly of the supporting components to check that it all goes together as intended

Also - a trial assembly of the supporting components to check that it all goes together as intended

Also - a trial assembly of the supporting components to check that it all goes together as intended

The internal support plates have to be split across the centre to allow assembly because the cylinder ends are a larger diameter than the barrel. A horizontal slot is machined at the half height of the cylinder corresponding with the longitudinal support plate leaving just a narrow connection between the two bores

On assembly a thin blade is used to cut the internal support plates so they can be fitted either side of the cylinder, valve chest and longitudinal support plate. The trial assembly shows the cylinder and it's back cover (made with the outside cylinder covers) in position.

The valve housing or steam chest is made exactly as those for the outside cylinders that was seen on Page 6, except at one end the flange for the crosshead guides is omitted and fitted after the part is inserted into the assembly. Also a flat is machined along the length where the side mounting plate abuts the steam chest

The valve housing is shown in place in the assembly

The inside cylinder assembly temporarily positioned in the frames showing how close the valve is to the inside face of the frame.

Before proceeding to the first soldering operation the exhaust passages from the outside cylinders are machined in the side plates

A side plate temporarily fixed with steel screws having run out of brass ones - again, showing the exhaust passage holes filed out so they point in something like the right direction

The top half of the internal support plates also support the underside of the exhaust passages which all meet under the blast pipe

They are shown here in what was expected to be there final position

The inside cylinders are nearly ready for the first silver soldering with the end plates roughly cut to shape for the smokebox saddle plate and the openings made for the exhaust passages from the front and back of the valve housing. Correcting fluid has been applied to those places where silver solder is not wanted.

The two cylinders are fluxed ready for the first silver soldering.

A cylinder in position in the frames after being silver soldered and pickled.

Machining the sides of the cylinder block to ensure the bore is exactly in the centre. The cylinder is mounted on the mandrel made from the pressure testing gear shown earlier and mounted between centres on the rotary table. The sides can then be progressively machined to close to the required spacing and the final cut to each side made with the sane tool setting. The same set up is also used for spotting the cylinder drain positions and spot facing for the flange plates to be located.

The exhaust passage walls are seen passing through the side plates with the 10BA fixings angling through. The Dremel is a very useful tool for drilling the holes for these, but temporary clamping is challenging.

The side walls for the exhaust passages were made up from brass sheet, cut to follow the cylinder and valve chest reasonably closely after being bent to shape in the horizontal plane. 10 BA brass screws were used to fix these in position for the next silver soldering operation.

The slide bar support has been fixed to the back if the cylinder, hopefully in the correct position, as there is little room for error at this point.

Finally the flanges for the cylinder drains are put on, and all is ready for the next phase of silver soldering.

The cylinders carefully treated with correcting fluid and fluxed ready to be silver soldered

After silver soldering and pickling

Templates being made for the floors of the exhaust passages

All floor sections in place for silver soldering

After silver soldering

Machining surplus material from the exhaust port walls and profiling the centre fin of the blast pipe base

The oval blast pipe flanges were machined from a block of bronze mounted on the rotary table in the milling machine