Progress Report No. 21 – Hunslet’s first trial in steam

Short Cut: Watch video footage coverage of the Hunslet in action!

For the full story, with illustrations, please read on.

For once, I am going to jump ahead of myself as there has been considerable interest following the heavy overhaul of my Hunslet 0-4-2T steam locomotive, No. 1187 of 1915.
Although I had taken delivery of the locomotive from K & H Ainsworth Engineering at Goulburn at the end of June this year, it was not practical to undertake steam trials on Pete’s Hobby Railway until sufficient track had been laid to enable real tests to be undertaken… As discussed in earlier Progress Reports, track construction had been delayed owing to continuing adverse weather conditions.

However, by mid-November, some 150 metres of track had been laid and partially ballasted. This involves the section fronting the street, across my driveway then around a 90 degree curve on a steeply rising gradient, to temporarily end at a point near the old stables, now my timber and coal fuel storage location. (It’s best that you have a further look at the track diagram accompanying Progress Report No. 7 again!). Construction of this extension will be covered in a forthcoming Progress Report. This gradient is steeper than I would like, but initially I was not over-concerned as normal train operations, once the circle is completed, would be anti-clockwise, so trains would be descending this grade.

A closer examination of the Boiler Certificate for the Hunslet revealed that it was certified for only 100 lbs per square inch, whereas the previous certification had been for 130 lbs – a 30 lbs psi reduction. It appears that the powers-that-be now have concerns about the old style lap-seam boiler design, which is the design of the boiler fitted to the Hunslet. Earlier this year, a blanket higher limit of 120 lbs psi was imposed on such boilers, with the view that generally this pressure should be limited to 100 lbs psi. This will affect all boilers of this design within Australia as their current boiler certificates expire.The result in my case (and of course all others) is a reduction in haulage capacity. The Hunslet’s pressure gauge has been marked with the new pressure limit.

My driveway front gate was closed so as to prevent the admission of the public to the site while the railway was being operated – a requirement under the National Rail Safety Law for “hobby railways”.

With some minor upgrading of the newly constructed track extension (mainly selective lifting and ballasting, together with slight super-elevation on the curve, trial runs were initially made with the 48hp Ruston diesel hauling the steam locomotive, dead. This provided for some consolidation of the track.

Last Monday (14/11/2016), I made the decision that the track was now satisfactory for steam trials. However, with temperatures in the low thirties centigrade, I held off until Wednesday when temperatures in the low twenties were forecast, along with some light showers. These would certainly dampen any sparks should they be emitted.

Rhys started cutting additional timber pieces for fuel and loading same into … well, the coal bunker, until I explained that the bunker was for coal and the hungry bars above the side tanks were to hold the timber fuel… the younger generation with no in-depth knowledge of steam! They have to learn somehow. Lenny was also present each day, upgrading the new rail track and also helping to load fuel, including lighting-up timbers.

Wednesday dawned somewhat colder than the previous days, with light showers falling. Light-up fuel was added around the cab floor. Rhys was also walked around the locomotive and shown in miniscule detail the lubrication requirements.

Shortly after 0930 hours, the Ruston was used to propel the Hunslet down to a point adjacent to the new Loftus platform site, where access was available to a water tap. A unique modification that I made to the Hunslet in earlier years was the ability to connect a garden hose to an inlet fitting on the boiler, thus enabling same to be easily “filled”. It took some time to reach a half glass – then the first problem of the day. This water connection was fitted with a non-return valve, preventing water flowing in the opposite direction, ie, out of the boiler. The trouble was, it didn’t! Ben had arrived by this time – he soon found that a small spring was missing, rendering the valve useless. A quick search of my spare parts found a suitable low-pressure tap, good for up to 150 lbs psi, which was promptly fitted in lieu. First problem solved. Only if any others would be as simple.

My previous practice was to light-up with a third of a glass of water, but this time, I had half a glass. The third of a glass would expand to half a glass by the time boiling point was reached a little less than two hours later, before starting to recede again.

Forty-five minutes after initial steam was created, the injectors would be able to feed water into the boiler, thus keeping the gauge glass at around a half. This first fire had been lit around 0945 however it was close to midday before kettle started to boil. The smokebox door had been left open to improve draught until sufficient steam was raised to activate blower. With a low-pressure blowdown (to clear sludge from the boiler), the opportunity was taken to let some water out of the boiler, otherwise I would still be waiting. As the pressure slowly started to build, the blower was activated and safety valves manually tested, then allowed to build up to maximum authorised pressure to check that they blew off naturally. Drain cocks were opened, followed by the throttle, still in mid-gear, to warm up the cylinders. During this time, after a few light engine runs, the Ruston was taken up the grade and placed at the far end of the track, adjacent to the stowed carriages and shut down.

A little after 1300 hours, with the drain cocks open, the reversing quadrant was placed in reverse and the throttle gradually opened… but, apart from a lot of steam from the cocks, nothing happened. Dead-centre! Close the throttle and place the quadrant into forward, open the throttle gently – the loco starts to move forward ever so slowly. Still moving and with the drain cocks still open, close the throttle, quadrant to reverse and open up throttle, and slowly the loco starts to move off in reverse. A short run along the level, to the eastern side of the driveway crossing and back again to a point clear of the station platform, so a second blowdown can be carried out. Mental note to alter the angle of the blow down from directly down on to the ballast, to an angle – also providing a safer access to the blowdown cock. With the cylinders warmed up, the drains can now be closed.

With more water in the glass, it was time to attempt the climb towards the former stables, now my timber and coal store. This was successful, although considerable steam appears to be escaping from the gland at the rear of the left hand piston. This is particularly noticeable in the attached video clip of the loco undergoing load trial, pushing the 48hp Ruston up the grade. In each case it, was not able to make the summit – on the other hand, the load is about double that of the four passenger carriages.

The opportunity was taken to carry out some sound level tests, which, despite the steam locomotive being worked hard, were within expectations. [In the video footage, you can see Nicholas at one of our sound check locations] The sound of a steam locomotive whistle only attracted two visitors – each with baby children, who watched happily from outside the fence.

As the clock approached 1600 hours, it was time to drop the fire – the Ruston was detached and run back to the carriages and stowed. The Hunslet was then run back light engine to join up with the Ruston. Rhys and Lenny had some difficulty in learning how to rake out the Ashpan, made a little harder now there is a lip to hold water in the pan to dampen the ashes. With the fire out and the boiler pumped full of water until the injectors cut out, the blowdown cock was opened and the boiler drained, so as to be empty and dried internally by the natural heat.

Problems to be looked at… gland packing on the left hand piston (this may also be from the admission valves) and dead centre difficulties. Solutions – examining the nuts and packing on the left hand piston, examination of the admission valves (but this can only be done with the aid of an inspection pit, yet to be constructed) and possible gradient easing. In the meantime, coaching load to be reduced from four to two vehicles prior to next trial.

I’ll let you know what transpires after our next trials in a week or two time.

Cheers,
Pete.

ps: if you haven’t already, don’t forget to check out the video footage of the Hunslet Load Tests.

Credits

All photos used in this Progress Report were taken using my camera, as I was otherwise fully occupied with the Hunslet. Photos 2016/4801, 2016/4805 & 2016/4920 were taken by Ben O’Malley. All other photos were taken by Rhys Harrison. Thank you, Ben & Rhys.