Tuesday 30 June 2009

New Platform at MOSI

Passengers boarding the first public train from the 2009 platform.

The Museum of Science and Industry in Manchester (which now likes to be known as 'MOSI') recently introduced a new platform for passengers boarding and alighting from the steam train which runs most weekends and some weekdays.

When I first became a member of the Friends organisation, back in 1988, the platform was near the main museum entrance, outside the Power Hall. A few years later, the running line was truncated and a new platform was constructed near the spiral stairs leading to the lower yard. We used this new platform until recently when another platform was completed. The latest platform is more or less in the position of the first platform (although it's now designed to serve the line nearest the Power Hall, rather than, as originally, the next road).

Looking towards Liverpool from the 2009 platform.

The line nearest the Power Hall has always had an inspection pit which has been refurbished. Since the pit is now on the running line, guard rails have been fitted. A small compressor house has been built just beyond the buffer stop and an air main feeds two charging points to allow the air receivers on 'Planet' to be recharged (the 'Planet' replica does not follow the prototype in having only a tender handbrake - the replica has a British Rail 2-pipe air brake system with 3 disc brakes on the engine and tender!). A modern ticket machine housed in a small wooden 'chalet' at the entrance to the platform allows passengers to purchase tickets for the ride before boarding the train.

On Saturday 27th June 2009, the new platform was brought into full service without ceremony and I was rostered as driver on that day, using the 'Planet' replica.

In August, the Museum is hosting a Transport Festival, starting on Saturday 8th August 2009. This festival concludes with the Great Garratt Gathering on 14-15-16th August. It's anticipated that the new passenger arrangements will be comprehensively tested during the Transport Festival.

Postscript: The Transport Festival is described here.

Thursday 25 June 2009

The Locksmith's House

Willenhall, in the West Midlands, was once the centre of the English lock-making industry which exported its products around the world. Although a small number of large companies eventually predominated, for many years small family businesses flourished. Richard Hodson and Son was typical of these businesses and, through good fortune, the family home and attached works became a lock museum, called The Locksmith's House.

In December 2008, regular public opening of the museum at The Locksmith's House in Willenhall ceased. Representations by various groups to the present owners, the Black Country Living Museum, have not succeeded in averting the closure. The museum claims that it will continue to open, as required, for party bookings. See the Official Website.

I visited the museum shortly before regular opening ceased to make an informal photographic record. It's a fascinating site, full of interest, conveying a real sense of the history of lockmaking in Willenhall and the lifestyle of the owners at the end of the Victorian era. It's sad that it can only be seen by pre-booked parties now.

My pictures of the Locksmith's House.

Monday 22 June 2009

Flying

I've already described my first flight which gave me the taste for flying and since then I've flown in a variety of aircraft.

That first flight was a private charter by one of my customers and later I was able to charter an aircraft myself. This is how it came about...

Having set up as an electronics consultant, I was trying (with no great success) to establish the business. One day, I received a call from a senior electrical engineer at a large company involved in building new plant for British Steel (yes, in those far-off days, we had a British-owned steelmaking industry). I'd worked with him before and he thought I might be able to help with a problem. It seems that another company had designed special electronics for bulk materials handling equipment which was failing to give satisfaction on site. The client, British Steel, was not amused and was demanding urgent action. I was invited to go up to the site in the North East of England and see what could be done. At the time, I didn't relish trying to put someone else's mistakes right (it was tough enough trying to rectify my own mistakes) and I said that I was too busy to travel to the wilds of the North East. But the engineer persisted and I was amazed to find myself saying "Oh, alright, I'll go and have a look, but you'll have to charter a light aircraft to take me there and back". I imagined that would be the end of the matter but, instead, I was told, yes, they'd pay for the charter provided I arranged it, as they had no experience in chartering. It seemed the wrong moment to confess that I'd never chartered, either. I was more confident that I could arrange a charter than that I could fix the problem when I got there.

I arranged a twin-engined Piper 'Aztec' and pilot out of Birmingham to a small airport a taxi-ride away from the steelworks. In the meantime, we collected as much information as we could about the problems that were occurring and designed a small control module to replace the key element of the existing system. Although we had to make a number of assumptions in designing our control module, I hoped that our replacement would at least furnish an indication of the way to go.

I can remember very little of the flight, except waiting in the old, cramped terminal at Elmdon before departure, along with passengers for the various commercial departures (this was in the days before there was a separate 'General Aviation' terminal for private flights). The other passengers were scurrying hither and thither in reponse to inaudible public address annonuncements but when my pilot arrived, I was politely asked "Are you ready to leave?" and the two of us went out onto the apron and made our way to the waiting aircraft. I liked the idea of sitting 'up front' in the right hand seat and wearing headphones ('cans') both to facilitate conversation with the pilot and to follow the Air Traffic Procedures. Basically, I was hooked on aviation!

And what about when I arrived at the steelworks on that charter trip? I'm glad to report that our hastily-constructed control module performed better than I'd dared hope and we subsequently did quite a bit of work at various steelworks supplying materials handling equipment of our design. I managed to charter small aircraft a few more times as well but that's another story.

Tesla's Legacy

Nikola Tesla (1856-1943) is one of the biggest influences on technical development in the 20th century but he died in poverty and relative obscurity. He fully accorded with the image of the "mad scientist" and was a prolific inventor. He had a brilliant mind and progressively became more and more eccentric. Although he became obsessed with the transmission of power without wires, it was his earlier work on rejecting Direct Current electric systems in favour of Alternating Current Polyphase systems which transformed our world.

Nowadays, when the developed world is completely electrified, it's hard to think back to a time when electricity was a novelty (not quite so hard for me: in the 1950s I lived for a number of years in a house without electricity). Production and distribution systems for gas became widespread in urban areas during the 19th century but the generation and transmission of electricity was still in its infancy. Direct Current systems were universal, partly because an important use for electricity was to produce mechanical power using an electric motor. Electric motors of the time needed direct current to operate - the alternating current motor was invented by Tesla around 1883 and started to be introduced around 1888, together with his Alternating Current Polyphase transmission.

When I was young, some parts of the country still used direct current (d.c.) transmission. When it was necessary to change the voltage, a rotary converter was used where the supplied voltage would drive a d.c. motor coupled to a generator producing the required voltage. This was complex and introduced power losses. The brilliance of the alternating current (a.c.) system is that voltage can be readily changed using a transformer - a completely static device. Even a transformer will introduce some power loss as heat but this can be minimised by careful design and choice of materials. The lack of moving parts and relative simplicity makes a transformer very reliable.

Even today, high-power electricity generation relies on rotating machines. Alternators (a.c. generators)are generally spun by turbines powered by steam (obtained by burning fossil fuel or nuclear reaction) to achieve relatively high efficiencies. Alternately, gas-turbines can be used. In smaller generators, it's possible to use reciprocating engines to spin the electric generator. In hydro-electric plant, a water turbine is used to spin the generator. In the case of (highly over-sold) wind generators, a big fan spins the generator directly.

The power is moved from place to place over wires. Copper is an excellent material to use, as it has little resistance to the flow of electricity. The resistance produces heat so, to minimise power loss through heating, the wire must be as thick as possible. These days, aluminium is also used. Its performance is not as good as copper, but it's cheaper.

Here's the attraction of a.c. transmission. Heat losses due to wire resistance can be reduced by increasing the transmitted voltage. For a given power, increasing the voltage will reduce the current. Voltage can be changed quite easily, using a transformer, to a higher voltage for transmission then, using a second transformer, transformed back to a lower voltage near the point of use.

Multiple transmission lines in Germany

The developed world is now covered by a 'Grid' of transmission lines, often at high voltages of 132 thousand volts or, in the case of the 'Super Grid', 400 thousand volts. Whilst voltages up to a few thousand volts can be carried in multi-core cables where the individual conductors are insulated from one another by plastic materials, higher voltages are normally carried by bare conductors in air, since air is a pretty good insulator. The conductors are carried on pylons, suspended from ceramic or glass insulator strings.

Electricity pylon routes marching across the landscape may not be elegant but they have facilitated the high energy consumption lifestyle which many of us enjoy.

Tesla wrote a number of publications, some of which have been reprinted, such as 'Tesla's Experiments with Alternate Currents of High Potential and High Frequency'. This was originally published in 1904 by McGraw Publishing Co., New York and reprinted by Lindsay Publications in 1986 (ISBN 0-917914-39-2).

There's a small collection of pictures showing various transmission lines.

Friday 19 June 2009

Railway Signalling: Spring Vale Sidings Box

A copy of the box diagram in its later form

Introduction:

Spring Vale Sidings Box was on the double-track Stour Valley Line from Wolverhampton High Level to Birmingam New Street. Catchem's Corner was the next box towards Wolverhampton and Deepfields the adjacent box on the Birmingham side. Spring Vale was an L.M.S. standard 'composite' box with a brick locking room and glazed, wooden operating floor. In addition to the Up and Down Main lines, a bi-directional Up and Down Goods Line extended from Spring Vale to Deepfields. There were extensive sidings on both the Up and Down sides of the main lines. The signal box commanded a good view of the steel works on the Up side of the line which gave rise to the box's importance.

The box diagram above shows the arrangement in the later years after changes associated with an ill-starred Steel Terminal built on the down side. Originally, a running crossover with single slip was provided on the Wolverhampton side of the box. After remodelling, motor points 2A/2B and the facing crossover 5/6 provided similar functionality. Originally, access to the Down & Up Goods Loop from the Up Main was via a scissors crossover. Following remodelling, separate crossovers 5/6 and 13A/13B provided similar functionality. The Bonding Diagram below shows the original arrangement.

After electrification of the line, Spring Vale Sidings box struggled on as a Shunt Frame for a few years but, like the steelworks it was built to serve, it has now disappeared.

The Steelworks:

In the early 1950s, I visited the Steelworks on an official tour which started my interest in steelmaking and heavy engineering in general. At the time, the works was universally known as Stewarts and Lloyds but it ended up part of British Steel and was eventually closed. Very little sign of a once-major employer remains.

There was one Blast Furnace, a post-war affair called 'Elizabeth' named after the then-princess, now Queen, Elizabeth. Once 'lit' blast furnaces are kept going as long as possible. A 'campaign' can last 10 - 15 years. The blast furnace produces iron from iron ore in a batch process. Every few hours, the furnace would be 'tapped' to release the new batch of 'blast furnace metal'. Originally, this would be sand-cast into 'pigs', allowed to solidify, then broken up and carried away for further processing which involved melting it again. In an 'Integrated Steel Works', blast furnace metal is kept molten and transferred immediately for further processing. The Spring Vale Works had a number of electric-arc furnaces, used for converting iron into steel.

As British Steel modernised, the more efficient Basic Oxygen Steel process was introduced at certain sites, together with new, larger blast furnaces which, whilst still batch-orientated, had a much larger throughput than 'Elizabeth'. So the Spring Vale works became less economical and closure became inevitable.

Signalling:

The box was provided with an L.M.S. standard lever frame unusally on the track side (because the brick base was 'undercut' due to limited clearance to the siding running behind the box). The lever frame stood about 18 inches above the floor. All the interlocking was contained within the Operating Floor in flat trays protruding to the rear of the frame. The catch handles were 'trigger levers' mounted behind the lever top (similar to old-fashioned car handbrakes). 'Catch Handle Locking' was provided so that, if a lever was locked, it was not possible to squeeze the catch handle against the lever top to release the catch prior to moving the lever. This prevented the signalman from 'taking a swing' at a lever which was locked, minimising the chance of injury. Nonetheless, I always preferred the older L. & N.W.R Webb design where locking was on the lever, not the catch handle. A number of levers in the frame were provided with electric lever locks or circuit controllers.

One feature of L.M.S. frames was that the levers controlling running signals for the main lines were grouped towards the middle of the frame, rather than at each end, so as to minimise the required walking by the signalman. At Spring Vale Sidings, the levers required for an Up Train were thus 20 (Home), 21 (Starter) and 19 (Distants). For a Down train, the "pull" was 35 (Home), 34 (Starter), 36 (Distants) and 37 (Distant).

Signalling at Spring Vale Sidings was upper-quadrant semaphore, wire-operated. The Down Starting Signal (with Catchems Corner Down Inner Distant below) originally had an ususual 'gallows' post but the limited remodelling changed this for a straight post with a 'Shunt Ahead' subsidiary signal below. Note that the lever number for the 'Shunt Ahead' signal was 33 - my diagram incorrectly shows it as 35. Originally, points were all mechanically operated via rodding but the limited re-modelling introduced electric operation of points 2A and 2B.

Absolute block signalling was in use on the main lines, using L&NWR instruments of Fletcher's 'DN' pattern.

The Down and Up Goods Line to Deepfields was worked 'Permissive', using special bi-directional single-line block instruments. Although each instrument had two block indicator needles, only one needle could be used at a time, according to whether the train was 'coming' or 'going'. In addition, the commutator which allowed the block to be set at 'LINE CLEAR', 'TRAIN ON LINE' or, when not in use, 'LINE CLOSED' also included a mechanical reminder device which displayed the total number of trains in the section in a small window.

I'm afraid I never did a detailed signalling diagram before the remodelling, but the diagram above represents Spring Vale in its final years as a block post.

Down Main Signals:

Spring Vale Sidings Down Block Section extended from Deepfields Down Starting Signal to Spring Vale Sidings Down Home Signal (35), just outside the box. 'Station Limits' extended from the Home Signal to the Starting Signal (34).

A Distant Signal is, of course, provided sufficiently far in the rear of the Home Signal to serve as a warning to the driver of an approaching train of adverse stop signals ahead. The location of a Distant Signal depends upon Line Speed, Gradients, Sighting Distance and train braking characteristics. If a Block Section is sufficiently long, the distant signal will be placed on its own post but where Block Sections are shorter (such as along the Stour Valley Line), the Starting Signal of the box in rear would often intervene so a distant arm was placed below the Starting Signal arm. A 'Slot' mechanism on the signal post would prevent the distant arm from coming 'Off' until the Starting Signal had cleared. The lever of the Distant Signal would work the 'Weight Bar' in the Slot mechanism, enabling the Distant Arm to clear once the Starting Signal is cleared. There's a bit more about 'slotting' here. A further Distant Signal would have to be provided under the Home Signal of the box in the rear, similarly 'slotted'.

In fact, Spring Valve Sidings controlled a total of three Distant Signals in the Down direction, all mounted under Deepfields 'stop' signals and 'slotted' by them. Lever 37 operated the weight bar for a Distant Signal 1144 yards from the Home Signal, mounted under Deepfields' Down 'Home 1' signal. You can imagine that getting the weight bar to move correctly at this distance required a certain technique. Lever 36 operated the weight bars for two Distant Signals - 36a (mounted under Deepfields' Down 'Home 2' signal) and 36b (mounted under Deepfields' Down Starting signal).

Up Main Signals:

Spring Vale Sidings Up Block Section extended from Catchems Corner Up Starting Signal to Spring Vale Sidings Up Home Signal (20), from where 'Station Limits' extended from to the Starting Signal 21).

Spring Valve Sidings controlled two Distant Signals in the Up direction, both mounted under Catchems Corner 'stop' signals and 'slotted' by them. Lever 19 operated the weight bar for Distant Signal 19b mounted under Catchems Corner Up Starting Signal. Provided the weight bar came 'off' correctly, a circuit controller applied power to motor-operated Distant Signal 19a mounted under Catchems Corner Up Home Signal. This motor-operated Distant Signal was 1190 yards from Spring Vale Sidings Up Home Signal.

Down and Up Goods Loop & Adjacent Sidings:

The 'third line' on the Deepfields side of Spring Vale Sidings was an up and down permissive block goods line. 'Permissive' meant that a second, or subsequent, goods train could be admitted onto the occupied line. To ensure the co-operation of signalmen at Spring Vale Sidings and Deepfields regarding trains on the Down & Up Goods Loop, stop signals at either end were 'Slotted' (in a similar fashion to slotting of Distant Signals described above) so that both signalmen had to operate their slot lever before the signal cleared. Lever 29 at Spring Vale Sidings worked the slot on the bracket signal allowing Up Trains to proceed to Deepfields. Lever 50 at Spring Vale Sidings worked two slots at Deepfields allowing Up Trains to approach Spring Vale. One slot was on the arm controlling facing movement from the Down Main to the Down & Up Goods; the other controlled the 2-arm miniature semaphore ground signals controlling movements setting-back from the Up Main to the Down & Up Goods.

The 'fourth line' on the Deepfields side of Spring Vale Sidings box gave access to a fan of sidings which extended to Deepfields. There was no block signalling on these sidings and the connection at the Deepfields end was very rarely used.

Typical working:

Whilst some boxes were only open during the daylight hours, Spring Vale Sidings worked three shifts ('Early', 'Late', 'Nights') most of the week.

A lot of the activity was concerned with the through trains. This involved accepting the 'Is Line Clear?' from the box in the rear ("Taking On"), obtaining 'Line Clear' from the box in advance ("Sending On"), clearing the signals in the order Home, Starter finally Distants ("Pulling Off"), observing the train as it passed, sending 'Train Entering Section' ("Section") to the box in advance, ensuring a tail lamp was carried, replacing the signals, giving 'Train Out of Section' ("Knocking Out") to the signal box in rear and waiting for the box in advance to send 'Train Out of Section'. Even this repetitive process could get quite demanding at busy times when trains followed one another on short headways and, of course, trains were being handled in both directions. Once freight trains, requiring to detach or attach wagons, terminate or originate at Spring Vale, were added to the mix, life could be quite hectic.

Signalling Controls:

There's a bit about the electrical signalling controls at Spring Vale Sidings starting here.

References:

For an earlier diagram of the arrangements at Spring Vale Sidings, refer to the Signalling Record Society publication 'British Railways Layout Plans of the 1950's', 'Volume 11: LNWR Lines in the West Midlands' (ISBN: 1 873228 13 9).

For details of the the Stour Valley line in 2005, refer to 'Railway Track Diagrams Book 4: Midlands & North West', Second Edition, published by Trackmaps (ISBN: 0-9549866-0-1). The First Edition of this book was published by Quail in 1988.

[Additional material added January 2010. New links added July 2013]

Sedgeley Junction remembered

In the post 'Sedgeley Junction', I talked about this signal box on the South Stafford Line. My friend Phil is contemplating a model based on the area and was recently interviewed on radio, appealing for more information, particularly about the Palethorpes operation.

So I've trawled the gloomy recesses of my memory for more information to 'add to the pot'.

The railway spelling of the placename - Sedgeley Junction - always intrigued me. The nearby 'Sedgley Road West' eventually leads to the town of 'Sedgley'. Both names get by with only two 'e' in the name, but the railway always used three in the name of their junction.

Sedgeley Junction controlled access to Palethorpes' private sidings. These sidings were situated on the Up side between Sedgeley Junction and Dudleyport Low Level station. There was a fairly basic loading platform with awning. The main factory was a short distance away. I'm indebted to John Dunn for this brief history of Palethorpes:

Henry Palethorpe commenced business as a butcher at Gooch Street, Birmingham, in 1852, where he was to develop a product that was to lead to the business becoming the largest producer of sausages in the world. In 1870 the business was moved to the Market Place, Dudley, as by then more production capacity was required. The business continued to grow, the year 1892 saw the purchase of premises formerley used as a brewery, belonging to Whitehouse Brothers, in Park Lane West, Dudley Port, later to be known as Tipton. These premises were known as the 'Model Brewery'. After extensive modification production commenced there in 1896, and continued until the 1967, when the company moved to a new purpose built factory in Market Drayton, Shropshire.

I believe 'Black Country Bugle' number 711 has an article about the demolition of the Park Lane West factory after the move to Market Drayton.

Palethorpes had its own fleet of railway vans, carrying the company name and a large picture of their sausages. Each weekday afternoon, these vans were attached to various passenger trains for distribution around the country and the unloaded, empty vans returned the next morning. There were no run-round facilities in Palethorpes' sidings so, when I used to visit Sedgeley Junction, two shunting locomotives would normally arrive at around the same time. In the morning, vans from two directions would be brought in and the two locomotives would co-operate in getting the vans positioned at the loading platform. In the afternoon, two loaded trains would be made up. As far as I remember, one train would head up the 'Third Line' to Dudley, the second would take the down branch to Dudleyport. At Dudleyport, further shunting would attach the vans to the required expresses.

Sedgeley Junction track diagram. Click on the diagram to enlarge.

The lack of a run-round and the inconvenient layout at Sedgeley Junction meant that there was quite a bit of 'fussing about' to get two trains away. In particular, the train for Dudleyport would be drawn up the 'Third Line' past the signal box by the engine for the Dudley working attached to the Dudley end of the vans. The Dudleyport engine (often a Stanier 2-6-4T) would then attach to the Dudleyport end of the vans, clear of the crossover. The points were then set for 'Up Main' to 'Third Line' and the Dudleyport engine would then draw its train onto the Up Main, clear of the facing points. Once the points were reset for the main line, the engine would propel its train past the box to clear the crossover points. 'Line Clear' would be got from Dudleyport for a '1-3-1', the junction points set for Dudleyport and the crossover reversed. The train would then depart on its short journey to Dudleyport. This move was invariably called 'the W move'. The lack of ground signals for shunting (except actually leaving the Palethorpes' siding) meant that all these moves were authorised from the signal box by handsignal - a raised arm given at an open window.

The freight guards who came with the Palethorpes' trains were kept quite busy by all this shunting. Freight guards jobs then were totally different from today. Railway staff who worked inside private sidings were frequently given little 'perks' by the businesses to ensure their co-operation. It was customary for the train guard to grab a snack at the Palethorpes' works canteen and, on one occasion, a friendly guard invited me to accompany him. The main works which housed the canteen was large and brick-built, four or five stories high and built right up to the pavement. The canteen was crowded and noisy but we were quickly furnished with bacon sandwiches.

Palethorpes' works was dominated by a tall brick chimney and, from time to time, this emitted what I found a very distasteful smell as a reminder of what the plant was about. Once, exactly what the business involved was brought forcefully home to me. I had visited my friend Tom at Sedgeley Junction on a Saturday and, checking the Special Traffic Notices, found that a special train was due to arrive at Palethorpes. The train duly arrived with about eight or ten cattle wagons and was 'loosed up' the 'Third Line'. The wagons were full of live pigs, all squealing. I still remember my sense of guilt as the train was slowly reversed down to the Palethorpes' loading dock where the pigs were unloaded to await their fate. In a while, the engine returned with just its brake van and, after performing the 'W' move, departed on the down main propelling the brake, 'rightaway Bescot'.

Normally, of course, the locomotive has to be at the front but the propelling of one or two brake van was permitted - the guard would usually be on the front verandah keeping a lookout. The 'Is Line Clear?' for an engine with one or two brake vans was '1-1-3'. Timetables usually used the acronym 'EBV' (Engine and Brake Van); railway staff called them 'Engine and Brake' or 'Horse and Cart'.

The Diesel Parcels Units (DPU) became quite familiar when I was working signal boxes. It was quite usual to see them with 'tail traffic' of a few vacuum-fitted vans. But I don't remember personally seeing a DPU hauling a 'Palethorpes' van, although there's photographic evidence that they did. DPU were quite common on the Stour Valley and the South Stafford Line on normal parcels trains but I never saw one go into Palethorpes'.

Dudley was a somewhat unlikely destination for day trips, mainly because of the Zoo. At Bank Holidays, a number of steam-hauled excursion trains would converge on Dudley from various towns, mainly in the East Midlands, so it was an interesting time to visit the box. Next time, I'll tell you a little about these excursions.