Compensating for Something

 ...Err, yes, actually! Thermal expansion, to be honest...

The saga of bench installation and 'finishing off' continues. The steel-topped bench, for which we dug into the rock in our previous post ("Benches" from 13th April), saw the holes being marked out for drilling. This ought to have been very simple, working from below and marking through the pre-cast concrete legs, to leave a mark on the underside of the soleplate. But, this being Kirkby Stephen, it was sat in a puddle, which needed bailing out first! Having duly accomplished this, we found that the marker did not fit through the holes! Fortunately, it was possibly to mark the holes from above, by alignment and measurement...

We then placed the two compensators in position and used a string line to get the alignment correct in relation to the rest of the rodding run. The marker was then used to pick out the centres for the holes we required drilling. A centre punch was then used, so the marks getting rubbed off in transit wouldn't matter! This allows better location of the cutters in the mag drill, using a sprung centre pin. With the mag drill set up, drilling was straightforward with sharp cutters (Yes - this was an issue briefly!) and soon we were able to place the plate on the legs and double check the alignment.

Jim polished up a selection of rodding pins, cleaned out the grease ways and checked / replaced grease nipples as appropriate, so we could assemble the compensators and connections. At times like these, using second hand materials becomes a bit of a lottery. Luckily, all the pins we selected were in very good condition. However, one of the compensator bases we'd cleaned up and painted had issues: the grease ways were blocked solid, and the threads for the grease nipples were too badly damaged for a tap to pick up. We swapped this out for now: at some point in the future we can look at a more thorough refurbishment.

At the point of assembly, we found I'd made the same mistake with levels as with the previous compensator bench built this way. Incorrect datum used! Fortunately (or not, in some respects), we had dug a little too deep, so needed to lift the legs up. Given that they were already partially buried, a good suggestion was made: to use the Iron Men and pull lifts to raise them up in a controlled manner, and pack whilst they were suspended in the CORRECT place... This was a bit of a faff to set up, but worked really well. Everything lined up nicely, and after a bit of fettling, we got everything bolted together, with pins in. 

At this point, we added another rodding stool to the run. We had left this one out (which sits between two benches), owing to the compact nature of this area, and not wanting it in the way! Chief Mole, Will, dug the hole swiftly.

Additional lengths of rodding were brought down and fitted to the run, enabling us to finally see something close to finished for this section. Some lengths of rodding that we've placed in situ DO require a bit of straightening, but we will attend to this later on, as we properly bolt things together.

The final job was to complete filling in around the bench legs, and dressing off with the ballast from elsewhere* - neat and tidy once again!

* see the next blog post