Progress Report No. 38 – Boiler Inspections

Short Cut: Watch video footage coverage of the Hunslet undergoing trials after the recent boiler inspection!

As covered in Progress Report No. 36, in mid-October last, Pete’s Hobby Railway Hunslet 0-4-2T B/n 1187 of 1915 was prepared in anticipation of its annual boiler inspection shortly afterwards.

At the time of the issue of the first boiler certificate following the locomotive’s overhaul at Goulburn, I had real concerns when the Boiler Inspector limited the operating pressure to only100 lbs psi whereas in previous years, it had been passed for 130 lbs although only operated at 120 lbs. As the overhaul had included work on the boiler, the massive reduction in safe working pressure was, to say the least, surprising. (See Progress Report No. 21). It also meant that the locomotive had difficulty on the rising grades of Pete’s Hobby Railway by simply running out of puff and coming to a stand, unable to lift the test load. This is evident in several of the video clips that have been posted to this web page.

Normally, one retains the same Boiler Inspector for each annual inspection as he is familiar with the boiler, thus is easily able to pinpoint any deterioration or otherwise that may have taken place during the previous twelve months. However, the use of the same Boiler Inspector is not mandatory. Thus, when he sought a fee of $1500 to make the trip to Junee for the October/November 2017 inspection, I began to look at alternatives as well as for a second opinion. Matt had suggested the use of the Boiler Inspector who surveys the boilers for Lachlan Valley Railway’s 3237 & 5917, as well as other locomotive type boilers. He was able to tie in an inspection of the Hunslet with a programmed trip to the area, so his charge would be only a tenth of the previous quotation.

Matt and his dad, along with other volunteers, had spent several days preparing the Hunslet for its boiler inspection, removing all washout plugs and giving the boiler the most thorough wash-out that it would have received in its life!

After a couple of changes in inspection dates, the Boiler Inspector turned up on about 48 hours’ notice. As he had not seen the Hunslet before, he gave it a really detailed going-over, including with the dome removed for an internal inspection. He used mirrors, reflected light and it seems every professional trick in the book before he was able to announce that in his opinion, the boiler and firebox were in excellent condition.

Image 2017.5025: As volunteers Bill and Rhys look on, the Boiler Inspector discusses various aspects of the regulator valves.

He also confirmed that the boiler was in fact not of the obsolete Lap Seam style construction (which placed the lower pressure restriction), but was instead Butt Strap Seam. The diagram below shows the difference between the two. Butt Strap boilers are understood to be some 15-20% stronger than a Lap Seam boiler which are now only permitted to operate to a maximum of 120 lbs psi pressure in Australia.

Diagram 1: Showing the differences between a Lap Seam and Butt Strap Seam join.

Accordingly he would have no difficulty in certifying the boiler for its original full operating pressure of 160 lbs psi – or in metric as it now has to be, 1100 kPa. Not that we needed this full pressure, 130 lbs is more than sufficient to meet the needs of Pete’s Hobby Railway. Whilst I am not sure, it would seem that the original Boiler Inspector had also treated the boiler as if it was fitted to a traction engine or road roller, where the boiler takes the stresses of supporting the front axle. On a steam locomotive, this is taken through the frame.

When completed, he congratulated Matt and his father, Bill, on the very clean condition of the boiler and firebox internals (the result of the extended washout previously covered in Progress Report 36). In his view, as the boiler and firebox were in excellent condition, he would have no hesitation in allowing the boiler to operate at its originally constructed working pressure of 160 lbs per square inch, or in modern speak – 1100 kPa! This was subsequently confirmed with the issue of Certificate of Inspection No. 24847. However, this pressure is not required for operation on Pete’s Hobby Railway. Accordingly the safety valves will be recalibrated to a lower pressure, probably 130 lbs psi, which will allow less strain and stress on the pressure vessel.

While on site, we had the Boiler Inspector undertake a preliminary look-see at the Fowler locomotive’s boiler. With some pad-welding in one location, he was of the opinion that the boiler should be able to obtain a full certificate of 160 lbs psi (1100 kPa). The engine is already in excellent mechanical condition, having received a full overhaul at the Sugar Mill for use as a standby engine back in 1965 (and basically never used), while I had also had replacement side tanks constructed when still at Loftus. That is not to say that a lot of work would still be needed to bring the loco back to life. Some options have been put to me as to how this could be done – and I now await firm proposals before making a decision.

Image 2017.5026: Volunteer Matt looks on as the Boiler Inspector peers into one of the wash-out plug opening on the firebox of the Fowler locomotive.

During the month the Hunslet was out of service waiting for its boiler inspection, a mother blackbird decided that a location between the side tank and the boiler was the most suitable safe place for a nest in which to bring her young into the world. Before we could steam the Hunslet again, the nest had to be carefully relocated to a safe spot on the static Perry locomotive. Mum didn’t like being relocated, but did accept her new location and subsequently brought three young into the world.

Image 2017.5028: Mum sitting on the nest within the Hunslet, prior to relocation.

Naturally, the days following the boiler inspection turned wet, with drizzle and showers. In order to protect Matt, Rhys, Ben and Caleb as they reassembled the dome and other plumbing, a temporary cover was erected over the locomotive.

Image 2017.5035: The last of the bolts holding the dome to the boiler is prepared for tightening.

It is surprising how quickly this laborious work can be undertaken when the promise of an early steaming was in the offing! As the mains water pressure was better where the loco was standing, it was decided to light up there, right next to my carport. Rhys quickly loaded our trolley with coal and using the ride-on lawn mower as a tractor, brought the load down from the fuel shed and then assisted in loading the bunker.

Image 2017.5039:As Ben and Matt look on, Rhys is about to lift the loaded fireman’s shovel up to cab height, to be dropped into the bunker.

Over the course of the next two days, both Rhys and Josh filmed the train operations. Rhys then combined the two into a single short video.

It can be easily seen that “Torpedo” was excited in having its boiler pressure increased and performed well with the higher grade Gunnedah coal recently received.

That’s your lot for this Progress Report.

Pete
Station Master.