Friday, October 20, 2017

Worth the wait– how to fit a bumper bar in a lock

I hope you think this post is worth the wait, but that’s not the reason for it’s title. 

There we were tootling down the S Oxford with our friends Jan and Stephen and thinking of our dinner booked at the Great Western in Aynho.  It was mid afternoon and we had our fingers crossed about getting a mooring.  Approaching Grant’s lock a man on a boat coming the other way shouted that we might have a long wait “some work going on at the lock”.  Indeed there was, and it cost us at least an hours wait, but it was worth it.  Not only that, but it ties this post very neatly in with my last one when I asked if anyone knew the name of those big T shaped bits of wood were on the CRT boat at Banbury the previous weekend.

Well they’re called Bumper Bars and the guys down in Grant’s lock were about to fit one.  here it is, in the lock and on the boat.

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As you can see, it now had its wacking gert iron slab bolted to it. I should like to have seen how that fitted that slab without losing a few fingers.  I wouldn’t like to guess the weight, but clearly lifting the whole assembly into place was going to be a non trivial task.  Grant’s lock has no road access, so a crane was out of the question.  The first job was to get the bumper facing the right way and at the front end of the work boat, so as you can see an RSJ was laid across the top of the lock and a chain hoist strapped to it and to the bumper.  With the chains tight, the water was then let out of the lock, so lowering the boat until the bumper was left dangling.

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Then the boat was backed off until the bumper was at its bow and the lock was refilled, laying the bumper down again.

Next, with the chain hoist unhooked from the bumper the RSJ was moved to the head of the lock, the boat moved up and the bumper reattached and the boat descended once more, now leaving the bumper where it could be re hoisted ready to be manhandled into position.

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The bar has to sit on that curved ledge by the top gate cill, but first they have to attached some retaining chains to the cill using some gert big iron staples. First drilling holes, then knocking the points in with a lump hammer and finishing off with a mighty whack from a sledgehammer.  In that confined space it’s nowhere near as easy as it sounds.

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At last. with the boat lowered and backed off, the bumper could be swung into place.  It needed a fair bit of persuading and in terms of elf and safety, some pretty dubious acrobatics by the lads, especially as the boat kept drifting backwards as they shoved the bumper forwards.

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The short retaining chains were then fixed to the bumper and it was all over bar the removal of the straps, in itself not an easy thing given where the bumper now lay,  and some general tidying up.

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Job’s a good ‘un as they say.

The CRT gang went on their way, declaring the lock open for business and we descended with a new found appreciation of what it takes to do jobs like this. 


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Well, I hope you enjoyed that.  We certainly did and it was well worth the hour’s delay, especially as there was still room at Aynho when we got there.

5 comments:

Carol said...

Great blog Neil, most interesting and as you say, a lot of work goes into these repairs and those men did an excellent job. Thank you.

Jennie said...

Thanks for this, Neil. It was indeed very interesting - I am not sure that many of us appreciate how hard some of these tasks are just to keep the locks working. Jennie nb Tentatrice

Marilyn McDonald said...

Always good to see how these things get done - I often wonder about the actual way things are hoisted/shoved into place.
One question in two parts:
* did the cill marker still reflect where a descending boat needs to keep forward of?
* and if not, did they paint a new cill marker?

OK it's two questions! And the reason I ask is that friends of ours in their 70 footer got their rudder caught in a lock where the bar had been fitted but the cill marker wasn't adjusted...

Cheers, Marilyn (nb Waka Huia)

Neil Corbett said...

Marilyn, No the new bumper was merely replacing and old worn out one, so cill marks remain the same. I believe the cill mark is based on the end of the curved brick ledge in any case, which is always clear of the bumper.

Vallypee said...

What a fascinating hour you spent. Isn't great to watch this big stuff being shunted around?!