Sunday, 20 December 2015

Alfred's last fling before Christmas

The weather has been unseasonably warm this autumn and early winter, but very wet as well. Today was an exception to that - clear blue skies, so Malc and I headed to Urmston & District Model Engineering Society track in Abbotsfield Park, with my 3.5" gauge Quarry Hunslet 'Alfred'

All pictures are copyright Jason Lau. Please click on any one for a larger image.

Abbotsfield park this morning. The left hand of the two tracks is the short inner running line we will be using. The main, much longer, running line passes along the far boundary.

Malc and I unloading the car on arrival at Abbotsfield Park this morning. I have already lifted Alfred from the car boot and placed him on the pneumatic platform. I doubt I could lift Alfred if he were any heavier, so for heavier locomotives the table can be raised and lowered by compressed air to match the height of a car boot so no lifting is required.

Alfred in the sunshine at Urmston this morning

Alfred being pushed from the pneumatic lifting table onto the swing bridge which can be swung into place across the Society's running lines. Before the bridge can be swung across the lines, LED indicator lights on it must be checked to be 'green' and not 'red'. Red indicators show that a train is within two signals of the bridge, so one waits until it has passed, and the LEDs gone green, before swinging. Once the bridge is in place across the running line, signals are set to 'stop'. If an approaching train runs past the red signals while the bridge is across the line, a siren will sound alerting one to swing the bridge back out of the way immediately.

Alfred is pushed off the far side of the swing bridge towards the traverser, with the club house up ahead. The main running line crossed by the bridge can be seen to the left of Alfred. The line immediately to his right connects the carriage sheds with the main running line, the line to the right of that is the inner shorter track that Alfred will run on today. The two lines on the far right run to the loco preparation bays. All these tracks are inter-connected by the traverser just in front of Alfred.

I position the traverser so I can push Alfred onto it, move the traverser right to one of the prep bay lines, then push him up to the prep bays accessed via a second traverser. When the traverser I am using (above) is in use, it leaves a gap in the inner short track. To obviate that causing an accident, the traverser cannot be moved unless the token for the inner track is inserted into it. When driving a train on the inner track the driver must be in possession of the token. The driver's holding the token ensures it cannot be inserted in the traverser, so the traverser cannot be moved to leave a gap in the running line.

Meanwhile, Malc carries the tools, battery, and other stuff up from the car to the prep bay we will be using. The battery is to power the blower used to provide a draught up the loco's chimney until steam is raised and the loco's own steam blower can take over.

I begin preparation of Alfred on one of the prep bays. The tender with its 3 water connections (one for each injector and one for the hand pump) has yet to be attached to the locomotive. 

The youngest Society member, Billy, works on his 'Polly' tank locomotive in the foreground while I work on Alfred on another prep bay. Malc is on his way to Alfred with the coal bucket to fuel-up the tender.

A 5" gauge Beyer Peacock tank engine arrives at the park. This loco is too heavy to lift so will make use of the pneumatic platform which will be set to the height of the car boot floor. The loco will be rolled out of the car onto the platform via a short metal bridging piece, then the platform height adjusted to match that of the swing bridge over the running line for the loco to be pushed to the prep bays. 

Before a steam locomotive is ready, passenger services are run by the Society's diesel-outline electric powered locomotive. Here, a full train is ready to leave the station on the main running line while I approach on Alfred on the short running line. 

 Me driving Alfred on the inner running line with Malc looking on (he got to drive later), while the Beyer Peacock is on passenger carrying duties on the main running track. Other locos are being prepared on the bays in the background.

 Me driving Alfred

0-6-0 tank 'Stepney' on a prep bay. The full size 'Stepney' works on the Bluebell Railway

Stepney shared the inner track with Alfred, here a delighted 6 year old handles the controls under direction of his grand dad!

The Beyer Peacock on the main running line which runs around the periphery of Abbotsfield Park.

Later 'The Beast' shared passenger duties, here driven by Keith. Malc and I have both driven this locomotive, and the Beyer Peacock tank engine which is sister engine to the one running today, on the main track on passenger trains with a qualified 'passenger' driver sitting behind us.

Stepney takes water on the inner track

The fascination of steam; a little boy and his dad are intrigued at the Beyer Peacock blowing off, as mum takes a photo. 

Keith, with his mug of tea. The other chap, Fred, is the all-important ticket seller for passenger trains.

 Fascination with steam (2); another little boy with his parents watch Keith firing 'The Beast'.

 A view across the park this morning. The club house is on the left, the carriage shed just out of shot to the right. The main running line is in the foreground and runs around the entire park passing along the boundary visible in the far distance. The inner running line is much shorter. It is the one furthermost from the camera and runs along the hedge beyond the trees in the middle distance. The line in between these two goes to the carriage sheds.

Abbotsfield Park showing the club house at the top of the picture, the inner oval track in the top left hand corner, and the much bigger main running line around the periphery of the park. It's quite a trek for Alfred, with his little wheels, to journey around the big track!

Here's a video made by the youngsters of Urmston which tells the story of the Urmston & District Model Engineering Society.


Monday, 14 December 2015

The age of the Jumbo Jet is drawing to a close

It's time to say goodbye to the Jumbo Jet, the aeroplane that changed the airline industry and took Concorde's crown.

In 1969 the world of civil aviation believed the future was going to be supersonic, and there was only one game in town; Concorde. But it didn't happen like that.

Boeing had produced a freighter in a bid to win a contract for the US Air Force. They lost, and the Lockheed Galaxy won. The civil market for a freighter was limited so Boeing cast around for a role for this behemoth, and decided to try to sell it as an airliner. Traditionally the airline industry had catered for a small but wealthy market; if you could afford it, you flew the Atlantic. If not, you went by sea and it took several days instead of several hours. Concorde was going to be very fast indeed, but also very expensive to travel on, which fitted this model well. The future looked rosy for the beautiful white bird and options for Concordes rolled in. Every major airline wanted to operate it.

However, all that was about to change. When the airlines saw Boeing's giant 747 Jumbo Jet, with over 500 passenger seats, they realised that the operating cost per seat would be a lot lower than on their narrow body jets so they could reduce fares and address a whole new, and much bigger, market. The ethos of the airline industry changed - the focus went off ever higher speed, and onto ever lower seat cost, where it remains today.

The Boeing 747 was the aeroplane that truly changed the airline industry, and in so doing brought about the financial death of Concorde. Every one of those options on the supersonic airliner fell away and in the end only fourteen production Concordes were built. Seven each for the two then state airlines of its producing countries, British Airways and Air France.

But now the mighty 747 is itself being usurped by the efficient new twin jets such as the triple seven.

'Business Insider' magazine continues the story.....

For more than 40 years, the wide-body jumbo jet ruled the skies. But with changes to aviation regulation, airline business strategy and improvement in turbofan engine technology, the days of huge aircraft are drawing to a close.

Since its introduction in 1969, the Boeing 747 has transformed the way people travel. With its ability to fly 500 passengers 6,000 miles, the jumbo jet allowed airlines to reach new destination while achieving profitability by lowering the per-seat cost of operation.

Over the years, the big Boeing was joined in the long-haul wide-body market by offerings from McDonnell Douglas, Lochkeed, and Airbus. In 2005, Airbus introduced the double-deck A380-800 — perhaps the most capable rival the Boeing jumbo jet had ever encountered.

But these days Boeing and Airbus are having a hard time finding new buyers for both aircraft. The cost of purchasing such a large aircraft, combined with the fact that they're relatively energy inefficient, makes them impractical.

Demand for the big jets has also dwindled as aviation regulations changed, airlines moved away from the hub-and-spoke model for their routes, and as jet-engine technology improved — making it safer for aircraft to fly long distances with just two engines.

In the last eight years, Boeing has sold just 45 jumbos — the majority of which are to be deployed as heavy freighters, and earlier this year Boeing announced it will be cutting back 747 production to just one per month. Airbus hasn't won an airline order for the double-decker jet since it sold Emirates a batch two years ago.

James Hogan, the chief executive of Emirates' rival Etihad was unequivocal when asked by Business Insider if the group will buy another four-engine jet.

"No, we're done," Hogan said. "We just believe in two-engine technology — they are much more efficient."

If fact, Virgin Atlantic CEO Craig Kreeger told Business Insider earlier this year that he's surprised Airbus was able to find as many takers for the A380 as they have.

Long-distance and transoceanic flights were traditionally exclusively covered by the 747 and its fellow three- or four-engine, wide-body jumbos because, when it comes to the engine count on an airliner, the thinking was that there is safety in numbers.

But as modern turbofan engines became more reliable, and engine failures far less common — the thinking, and the regulations changed. As a result, most airlines have turned to twin-engine mini-jumbos that are more fuel efficient.

Furthermore, airlines are moving away from the "hub and spoke" business model that calls for massive numbers of the passengers to be routed through a single mega-hub. Smaller, fuel-efficient jets such as the Boeing 787 Dreamliner allow airlines to offer passengers nonstop, point-to-point service without transiting through a hub.


Sunday, 13 December 2015

No steam today, but a lovely lunch enjoyed.... and a buffet missed

Chris and I enjoyed a superb lunch today at the Edge Hotel, Alderley Edge.

The weather was not good for running steam locomotives, but today was Urmston Model Engineer's Christmas lunch. Jason Lau took some pictures, though, and I hope to attend next year's event.

A bit of excess water in the cuttings after the days of rain we've had. Note the dual gauge track; 3.5 inch and 5 inch. Alfred runs on the 3.5 inch gauge lines.

Because of the poor weather and (probably) the buffet in the club house only two steam locomotives were there today. Keith, with 'The Beast', and Dave with his Beyer Peacock tank loco, both of which Malc and I have driven. Here they are being prepared on the prep bays. 

We have passengers to haul before the steam locos are ready, so the club has a diesel outline electric powered locomotive to work the first trains of the day 

Two members enjoying the lunch. Eddie, on the left, is an ex BR steam driver and a fellow member of the Manchester Locomotive Society with myself and Malc. Eddie owns a lovely 5 inch gauge Midland Compound 4-4-0 locomotive, and a green Black Five with BRITISH RAILWAYS in capitals on the tender sides! I thought that an oxymoron when I saw it (Black Fives are always black), but in 1948 BR apparently painted three Black Fives in various pre-nationalisation shades of green (GWR green, SR green, and LNER green) before deciding they should all be black after all. Eddie drove the LNER green one which was shedded at Edgeley (Stockport), so that's the one he modelled when he retired.

Good spread!

Members enjoy the buffet 

It looks as though the club house was quite full!


Sunday, 6 December 2015

A little 'Alfred' maintenance, then a nice run today at Urmston.

While running 'Alfred' at Urmston club track we'd noticed the right hand injector was reluctant to pick up. Injectors are magic devices that use steam at boiler pressure to inject more water into the boiler, against that boiler pressure! That sounds impossible, but they use cones to vary the pressure and velocity of the steam and water in the device, and also liberate energy from the steam by condensing it into water, releasing the latent heat. 

Injectors can use live steam (taken from the boiler) or exhaust steam (steam exhausted from the locomotive's cylinders). Full size main line locomotives usually have both types, but each of 'Alfred's injectors use live steam. Exhaust steam injectors are really only appropriate on locomotives that run considerable distances at reasonable speeds, ensuring a reliable supply of exhaust steam.

The steam and water supplies are controlled by driver-operated valves in the cab. Injectors have a steam cone, a combining cone, and a delivery cone as shown in the diagram below:

This is the right hand injector, outside the frames and under 'Alfred's cab. The left hand injector is in the same position on the other side of the locomotive. The steam feed (controlled by a driver-operated valve on the footplate) connects to the right hand end of the injector, the feed water from the tender (also controlled by a driver-operated valve) enters the injector from underneath, and the outlet to the boiler is the pipe connected to the left hand end of the injector. The water overflow pipe is to the left of the feed water input pipe.

When the driver (or fireman on a multi-crew engine) decides the water in the gauge glass is getting a bit low he will operate one of the injectors to put more water into the boiler. This is the most important job on the locomotive and takes precedence over anything else. If the water level is allowed to get too low, the top of the firebox crown inside the boiler is exposed, and with the roaring fire in the firebox beneath it, and no water over it to conduct away the heat, the crown will melt and collapse. With the boiler at a working pressure of 90 pounds per square inch (psi) on 'Alfred', or perhaps 250 psi on a large locomotive that will result in a boiler explosion. The energy released when a boiler full of water at perhaps 180 degrees centigrade instantly boils to steam as the pressure reduces to atmospheric is devastating and often fatal.

Locomotives always have more than one method of filling the boiler when it's at working pressure, usually multiple injectors. Alfred has two injectors, plus a mechanical hand operated feed pump mounted in the tender.

To operate an injector, first the feed water is turned on, and can be seen pouring out of the water overflow pipe on the injector. Next, the steam supply to the injector is turned on, and the water valve turned down until the injector 'picks up' Thus is confirmed by water ceasing to dribble from the overflow, and a satisfying gurgling singing sound as the water is injected into the boiler. When the gauge glass level is back to where it should be, the steam supply is turned off, followed by the water supply. Never the other way round - if you run steam through an injector with no water supply it will get hot. And hot injectors can't condense steam, so won't pick up. If you do it inadvertently, you have to run water through it until it cools down.

On 'Alfred' the right hand injector has always been more reluctant than the left hand one to 'pick up', but latterly was refusing to work at all, simply spitting steam or water from the injector overflow. One cause can be the cones (which, on these miniature injectors, have tiny orifices) can get partly blocked by scale deposited on them in use. The feed water comes through fine gauze filters in the tender so blockage by particles suspended in the water is unlikely. The cure for scaled-up injectors is to remove the unit and 'pickle' it in citric acid or vinegar which will dissolve the scale without harming the metal of the cones. So last week, off came 'Alfred's right hand injector.

The disconnected pipes once the injector was removed. The glass in the foreground isn't a whisky and soda, it's pickling solution with the injector in it (an initial 20 minutes in citric acid solution, then a rinse with water, followed by an overnight bath in vinegar).

Here's the injector getting a water rinse before refitting to 'Alfred'. The delivery cone has come out of one end on the device and can be seen in the water, along with a small collar which fits on the steam inlet end of the injector.

A closer look at the injector connections; steam input on the right, water input in the middle, feed water out to the boiler on the left.

When the water leaves the injector for the boiler, it passes through a non-return valve called a 'clack'. 'Alfred's clack valves comprise a small metal ball held against a seat in the valve by boiler pressure. When the injector forces water into the boiler it unseats the clack ball because the injector output pressure is higher than boiler pressure, allowing the water to feed into the boiler past the ball. Once the injector is turned off, boiler pressure seats the ball again preventing the boiler from blowing back through the clack and the injector overflow, emptying the boiler!

Sometimes a particle of boiler scale will find its way into the clack and prevent the ball from seating. This can often be rectified by turning on the injector again to flush through the clack, and / or banging the body of the clack valve with a wooden tool handle (not a hammer! We don't want to damage the clack!).

The function of the clack can be tested while the injector is off the locomotive and loco is not in steam. By attaching a plastic tube to the pipe that's normally connected to the injector output one can blow through the clack, but on sucking the ball should seat preventing any further sucking. When I tried this on 'Alfred' I couldn't blow through the clack, so decided to have a look at that valve.

'Alfred' has three clack valves; one for each injector and one for the hand feed pump. They are mounted on the back of the boiler and look like small vertical brass cylinders with a hexagon nut on top which is the lid. The lid can be unscrewed to gain access to the ball and its seat. The right hand clack is clearly visible in the picture above, just in front of the fire hole door. The left hand clack can also be seen in the background. The clack for the hand pump is the same as these two but is mounted lower down on the boiler back plate, beneath the footplate floor.

On unscrewing the lid of the right hand clack and shining a torch down it, the ball could be seen. It was stuck to its seat which explained why I couldn't blow through the clack and why the injector would not pick up. I nudged the ball off its seat with a spring hook, took it out and cleaned it and the seat with vinegar, put the lid back, and did the blow and suck test again. This time it worked just fine!

The injector back in place on 'Alfred'

Today I took 'Alfred' to Urmston club again (Malc had a prior engagement at the motorcycle show at the NEC, so it was just me today). Once I had steam pressure up I tried both injectors. The left hand one worked as it normally does, and the right hand one picked up OK. It does require the water to be turned on fully and on turning on the water it dribbles, rather than flows from the injector overflow as the left hand one does, so for some reason there seems still some sort of partial obstruction in the injector, though on turning on the steam the water flows faster before the injector picks up. Might have to do the citric acid thing again or replace the injector... But at least it now picks up and delivers water to the boiler.

I had a great day running 'Alfred' round the inner track for many circuits at a time, only stopping to top up the tender water tank or the coal supply in the tender. I think driving him is becoming 'automatic' now and there is no longer that frantic feeling that there's a lot going on and not enough time to attend to everything.

I also found that 'Alfred' is happy to run 'notched back' to the maximum his indented reverser lever in the cab allows. The reverser has 7 positions; full forward, one notch up in forward, 2 notches up in forward, mid gear, two notches up in reverse, one notch up in reverse, and full reverse. In 'full forward' (or reverse) the cylinders receive steam at boiler pressure for pretty much their entire stroke. As the driver 'notches up' the admission of steam into the cylinders is cut off by the valves before full stroke, cutoff being earlier the higher the 'notch'. This is analogous to changing up through the gears in a car as speed increases. When a locomotive is notched up, the steam expands in the cylinder after inlet valve cutoff, reducing its pressure as it releases energy, so a notched-up locomotive is far more efficient than a loco in full forward gear (or reverse - it works just as well either way) as it is using expansion of steam in the cylinders to do work. However, a Locomotive will not start from a stand in high cutoff any more than a car will happily start from a stand in top gear, hence the 'reverser' lever. And heavy loads or steep climbs may require cutoff to be reduced to prevent the loco stalling.

This explains why a locomotive on pulling away from a standing start 'chuffs' or even 'barks' quite loudly, whereas one at speed 'purrs'.

Mid gear admits no steam to the cylinders - neutral in car terms.

It would be interesting to know what 'Alfred's cut off is in percent terms at 'two notches back from full' (one notch away from mid gear). He certainly ran very well in 'top notch' today, and it noticeably reduced the water and coal consumption from running in full forward. Interestingly, he would not run at such a high cutoff on rollers when I steamed him at home, tending to run rough and oscillate. The momentum of 'real travel' provides the 'flywheel effect' that allows smooth and efficient running at high cutoffs.

Jason Lau's pictures of me preparing 'Alfred' on my own in the rain this morning at Urmston. The weather cleared up by lunchtime.

'Alfred' back in the garage again tonight.

There's still a bit of experimenting to do, especially with firing rates to find the optimum sized fire - not too thick which restricts airflow through it which leads to an inefficient burn and risk of clinkering, and not too thin which means it'll burn through quickly with a risk of going out if you don't catch it in time.

The club boiler inspector completed the boiler test certificate today, so 'Alfred's paperwork is up to date. The boiler hydraulic test (pressurising the boiler to double-working-pressure with water and checking for no leaks) is due every four years, and the steam test once a year (checking the safety valves lift at maximum allowed boiler pressure and will relieve excess pressure even with the blower fully on, and that there are at least two working methods of getting water into the boiler). Both were successfully completed on 'Alfred' in October, just before I bought him, but completion of the certificate itself lagged behind.