Saturday, 23 May 2015

Achilles Report No69: Hydraulic & Steam Tests...

Hi everyone. Welcome to another "Achilles" report. Today the locomotive was at Ryton Pools for some official business: two exams to be precise. Though her tickets have yet to expire, I decided to have her tests done slightly early to allow for repair if (God forbid) she failed. The locomotive would have both her hydraulic test (every 4 years) and her steam test (every year) this afternoon. The process of examining pressure vessels and declaring them safe is something that is growing ever tighter. In some circles even Mamod boilers of no more than 15psi require testing. With loco's the size of "Achilles" however, the testing procedure has always been this way, barring a few alterations over the years. The locomotive was unloaded just after 1pm and duly rolled onto the steaming bays...
For the hydraulic test, the boiler is pumped up with water until pressure is made to one and a half times (135psi in our case) the working pressure (90psi). I believe the boiler has to hold this pressure for 10 minutes without blowing anything. In order to undertake the hydraulic, the pressure gauge is removed and blanked, all fittings are shut and the safety valves are blanked in favour of a special fitting to connect it to the test kit. The smokebox is also open and the grate/ashpan removed for inspection before and during the test...
The test kit pumps water into the boiler and maintains pressure against a calibrated gauge...
The locomotive held its 135psi very well and was leak free, much to my relief...
With the hydraulic exam passed, its time to refit the safety valves and grate in preparation for the steam test. The pressure gauge is also tested against the calibrated test gauge in order to make sure it reads right. With the pressure gauge cleared and refitted, we can raise steam as normal...
During the steam test, the safety valves must blow when required and must also hold the pressure at the red line with the blower on full chat. The handpump is also tested for operation as are the fittings and axlepump. Throughout all of this the boiler is again checked for any leaks or fizzes. Thankfully there were none and the loco passed: hurrah!...
With the riding truck attached and a clear track ahead, the loco is off to prove the axlepump some more. She is spotted here at Ryton Halt with the valves lifting...
Here is a clip of the loco chugging around the track with the spark arrestor hat on...

After a good few laps, some of which even saw Ken having a little drive, the loco performed very well. Ken reckoned he hadn't driven the engine for about 10 years! Here she is on the steaming bay again whilst being disposed...
So that's it, the tests are over for another year. The steam test is due in 14 months and the hydraulic is due in 4 years. I'm very pleased that she's passed, that saves any undue worrying in the near future! The loco was soon back home and ready for a good polish. Thanks for reading everyone. Best Regards, Sam...

2 comments:

Lee Griffiths said...

Useful post as I'm about to do a hydraulic test on a A1x recently purchased with no boiler history :) wish me luck

Sam Brandist said...

Good luck! :D Lovely engine the A1X