INSIDE MOTION No 13 March 2021

News and Views from the
TYNESIDE SOCIETY of MODEL and EXPERIMENTAL ENGINEERS

Download IM document in PDF format here

Preamble

On Monday 22nd February, the Prime Minister outlined the Government‟s cautious strategy for emerging the country from the strictures imposed because of the Covid-19 pandemic. The Committee will be meeting in early March to consider how best to take things forward.

At least now, together with the vaccination programme well underway and the days lengthening, there is a sense that the worst may finally be over.

Member’s Musings

The Chairman’s Current Build

Peter Newby

My lockdown project is the completion of a Martin Evans 3 ½ – inch Jubilee – a misleading name as it has nothing to do with the LMS Jubilee class but is a celebration locomotive for the Model Engineer Magazine 60th Anniversary. Serialised in Model Engineer from 1958 until 1959 it‟s one of Martin Evans early and more successful designs. I have always wanted to build this locomotive after seeing two models at Sunderland Model Engineers track around 1972. One was a very fine example by the late George Heslop.

I have cheated a little in that I took a chance and bought a rolling chassis off eBay, which came from Bangor, Northern Ireland. It was a very well made, but rusty, with wheels and axle boxes plus the leading pony truck. The rear 4-wheel bogie plus all the cylinders, motion and everything above the chassis was missing. The chassis was stripped, de-rusted, painted and re-assembled with the correct springs and hardware.

To again speed the build laser cut coupling rods, connecting rods and motion were used – while this still required a lot of machining it saves some very tedious work. The chassis has been run on air, the lubricator made and fitted plus the brake gear made and installed.

The linkage and cylinder drain cocks seemed to be a rather complicated arrangement adding more bits to an already tight space. Some time ago Gordon Bullard gave me a drawing of an automatic drain cock design that was both simple to make and install – four of these have been made and installed. Time will tell of their merit, but running on air they seem to work well.

The boiler is now well on its way just requiring Stuart, once we are back up and running, to do his magic and glue it all together. I was very lucky and Jim Stephenson gave me a number of laser cut parts including the tank sides and a number of the smaller bits. Brian Nichols gave me a set of flanged boilerplates, all of which have saved a great deal of work.

The LMS 2-6-4 tanks started with Fowler‟s parallel boiler design and each successive Chief Mechanical Engineer (CME) tweaked the previous incumbent‟s design right up to Robin Riddles as CME of BR.

My model is going to be No.42429, which was the locomotive on Carnforth platform in the 1945 film “Brief Encounter”, and one of the first batch of taper-boiled Stanier designs.

In Northern Ireland the Northern Counties Railway (a LMS subsidiary) had 2-6-4 tank locos built by the LMS at Derby with a parallel boiler. These were 5ft 3in gauge and there is one still in preservation and running. Because of their versatility they were nicknamed “Jeeps” and were seen all over the northern Irish system. I suspect, but do not know, that my chassis originating in Bangor was possibly going to be built as a Jeep.

All the Stanier 2-6-4‟s were cut up in the „sixties apart from one – a three-cylinder example – which is in the National Railway Museum in York.

To complete a model that someone else has started but not finished for what ever reason gives me – and my avoid-waste personality – a great deal of satisfaction in seeing it completed as the previous builder envisaged.

I hope you have found this description of the Martin Evans Jubilee locomotive informative and not too boring. For anyone interested, I have a number of surplus castings and parts which, for a small charge, I would be pleased to pass on.

Automatic Drain Cocks to Gordon Bullard‟s design (see also TSMEE News November 2019 for Gordon’s article – Ed)

Gyrocoptors

Michael Mee

While most things that appear from the workshop are steam locomotives, there are many other creations that see the light of day and if you look closely at the photo you will see one of the rarer ones. No its not a helicopter, no tail rotor and a propeller pushing it forwards, its a Gyrocopter, the predecessor to the helicopter and the strangest thing about it is that the rotor is not powered in flight.

This is a relatively modern version with a fibre-glass pod, the earlier ones from 50 years back had a simple seat more akin to a deckchair, and oh boy, is the view good from them !

Looking closely at the photo shows the simple construction. There is a fore and aft keel, an axle for the main wheels and a vertical mast, these are 2” square aluminium tubes to which are attached the engine, rotor head, seat or pod, various aluminium angle bracing parts and of course the tail assembly. Because the airframe is so simple it is possible to assemble quickly and cheaply, all the aluminium was obtained locally in Byker. Ok – the engine, a Rotax 912. is not cheap, nor the rotor system, but compared to other aircraft this is both quick and cheap to build, and it is definitely different.

So what can it do? Cruise speed is 70 – 80 mph, (test flying showed 115 in favourable conditions) 3 hours duration giving a little over 200 miles range and a ceiling of 8000 feet. Autogyros do not have a stall like conventional aircraft and can safely be bought back to zero airspeed, but you will be descending at about 10 – 15 mph, similar to an older style parachute, and under full control. They are highly manoeuvrable above about 30 mph, and wow what fun to fly.

So just how does an unpowered rotor fly? Lets take the gyro up to about 1000 ft engine to idle and airspeed back to zero, try to avoid going backward they weather-cock 180 deg pretty smartly if you do ! ( It also brings on one of those “what the heck just happened there” moments ! ) The rotor will be doing about 320 rpm while you descend gently at about 10 – 15 mph. Remember this – air flow over a flying surface produces lift at 90 deg to the air flow. The rotor tip is doing about 300 mph with 10 – 15 from below, so the resultant air flow is just slightly below the blade, plenty of lift, and some drag trying to slow it down. Now if we look at the rotor nearer the centre we find that the airflow on the front of the blade is now slower but still with 10 -15 from below, so the resultant airflow is now approaching the blade from an angle below the blade, which means that the lift is leaning forwards and pulling the blade round, this is the engine that drives the blades. Further in still the blade is stalled and of no use to us. Normally gyros fly with the rotor leaning back about 9 deg which allows a slipstream to enter beneath the rotor, above about 35 mph you will be able to climb.

Rotor speed is primarily set by the mass hanging below it, if you do a tight turn, pulling some G it will oblige and speed up during the turn, they do not like height or low barometric pressure or really hot days, At 8000 foot the rotor speed went up from 320 rpm to just under 500 and the Red Arrows formation passed low level beneath me ! Way outside my comfort zone !!!

A little gem for you! All the early gyros were single seat, so how did you get a trial flight or learn to fly them? Answer- the first time you ever went up in a gyro YOU WERE THE PILOT!!! no I‟m not kidding. The training regime involved taxing up and down the runway learning how to balance the gyro on its main wheels only, this is the attitude that it flies in, when mastered a little extra power and it leaves the ground by a few feet which you may not even notice initially, reduce the power and you‟re back on the deck.

Eventually the instructor, when he felt you would probably survive the trip, allowed you to use full power and do one circuit. Your first gyro trip and you were the pilot! It was a surprisingly successful training method, the faint hearted never went anywhere near it though, it did help to be a bit mad, I never heard of any fatalities, but there would have been a few bent gyros.

It was a happy time mainly on the photo gyro, but nowadays it‟s all changed with two- seat ready made machines, expensive, and two seat training is also expensive.

Managed about 500 hours all over Cumbria, Northumbria and parts of Scotland, even down to Bedford to a rally. The best trips were when about six of us set off on a long trip like a swarm of gnats.

Ah, Happy days.

ps. If the madness has got to you, they train at Kirkbride, west of Carlisle

Historic Railway Bridge Destruction

Phil Page

Highways England Historic Railways Estate (HRE) plans to rapidly expand its demolition programme of redundant railway structures. This is presumably to help reduce the cost of ongoing maintenance. The list attached shows 135 structures in the first tranche as published by HRE Group:

and a map:

https://www.google.com/maps/d/u/0/viewer?ll=54.497867611651664%2C-2.141808848720559&z=10&mid=14uBPUTgoOoCWI0VKCAIDg-nc5zDHSE9M

Some of these bridges are on aspirational route extensions for Heritage Railways, others could be on lines suitable for reopening to extend the national network if the Government is serious about extending public transport use and reduction of carbon dioxide emissions. Others may have value as cycle-ways.

Highways England appears hell-bent on the wholesale destruction of the nation‟s heritage. A lot of these are masonry structures, built with skills and materials from a bygone age and mostly 150 years old. They survived Beeching, but once they are gone, they will never be rebuilt in the same way if ever required again. Other bridges that are not on the list are likely to follow in subsequent tranches. Local authority “protected railway route” status may not offer sufficient protection. Highways England‟s remit includes Scotland and Wales.

It is important to note:

“It is understood that Highways England has already notified local planning authorities of their intention to progress 124 schemes under permitted development powers which are only applicable when there is a threat of “serious damage to human welfare” involving the potential for death or injury. This approach circumvents the need for planning permission’

This means that the public will not necessarily be made aware of the proposals, nor have any opportunity to object as would be the case with the normal planning consultation process. You won‟t know until a contractor turns up on site, then it will be too late. This was the case with Chilcompton Bridge on the S&D mentioned in the Rail Engineer report.

Quite Interesting

Cliff Walker

The more observant folk enjoying their daily exercise on a St. Ives Bay beach in Cornwall may have recently noticed a strange object jutting out from the cliff-top. It‟s the remains of a (probably) 100-year-old mine cart and a pair of rails associated with the Gwithian Tin Sand Works.

Credit and full story – https://www.cornwalllive.com/news/cornwall-news/gallery/history-100-year-old-cart-5001747

Postamble

Thanks to Peter Newby and Mike Mee for their contributions, which had actually been held over from December and January respectively. Without these two, and a couple of acquaintances of Hugh Janus, there would have been nothing at all to publish. The editorial cupboard is now truly bare – please consider sending something, however small, to make the next issue possible. By then, there might be some news about resuming Club activities

Contact information
  • Newsletter Editor – Mike Maguire – mike.maguire@btinternet.com
  • Club Secretary – Linda Nicholls – lindanic@sky.com – 01 670 816072
  • Website – www.tsmee.co.uk
  • Webmaster – John Rowley – johnrowley@btinternet.com

Headquarters and Multi-gauge Track – Exhibition Park, Newcastle upon Tyne NE2 4PZ