Friday, 16 August 2013

The Day We Sprung Into Action...

Hi guys. Today, after work, I made my way over to Shackerstone where a portion of the Steam Department had been called together in order to undertake a repair task. The Great Western No3803 had failed last Sunday with a reported broken spring and, with two spares on site, we had at least one to change! The engine is reported to "like" breaking springs but I think in a way this has probably come about as many people forget just how many wheels this thing has got! The engine carries 16-wheels in total, from buffer to buffer - all of those have leaf springs; 8 of which carry a fair old amount of weight as they are driving axles. A few springs a year out of 16 doesn't seem bad to me when an engine like "Sir Gomer" may only break one a year...though she only carries 6 in total!

The process of changing a spring on this big engine involves, of course, jacking her up. The front and rear of the loco is jacked up using very heavy lifting jacks with very heavy sleepers as packing. The very heavy locomotive slowly begins to rise, millimetre by millimetre...groaning slightly as she does so. In the pit underneath the engine you can get a good view of all of the driving axle springs and also check them for damage/condition. Tapping each leaf with a small tool hammer will often show up damage as the leafs will begin to separate if the spring is broken. The springs are fastened to the bottom of the locomotive by three pins. The outer two pins are attached to the loco's frames via a bracket, one of which is riveted to the frames whilst the other is nut & bolted. Below shows a picture taken last year on 3803 with a spring in view beneath an axlebox. The bracket is the right-hand one and so is riveted to the frames, with the right-hand spring pin being visible to the left of it...
"Spring" - by Jan Ford
The central pin goes through a hanger for the main spring buckle. Anyway, where the locomotive is high enough on the jacks is decided by tapping either of the two outer pins with a small hammer to suggest movement. When they start to move, the loco is high enough. The two outer pins hold up a hanger which is threaded and allows two large nuts and two pieces of packing to pull the spring against the bracket, thus holding it still during use. This is how the locomotive holds itself on the spring (via the framing), whilst the central pin holds the axlebox in turn...and there is locomotive springing! In short the three pins allow the locomotive to stretch the spring with its weight and this gives the locomotive some form of suspension. With the two outer pins out the central pin is the last and this is whacked out before the very heavy broken spring falls away. The very heavy new spring can then be brought in and fitted by people who are, shall we say, better built for carrying or lifting very heavy things. Us skinny, muscle free folk can then move in and bolt up the very heavy spring now that the very heavy part is nearly over. With everything tightened up and all pins and brackets firmly attached and secured, the locomotive can be dropped back down. Its quite a sound as the big engine groans its way back down onto its 10-springs. And that's it...a job well done!! Don't get me wrong...I may have mentioned it before but...this is a very heavy task...don't try this at home! Cheers guys, Sam...

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