So How Does This Work?
As I remarked in an earlier post, the Giant has no means of self-propulsion and relies entirely on the work of tugs to both tow it out to sea and to advance the cable laying operation. This is effected by the use of anchors - the tugs picking up and re-setting the anchors and the Giant reeling them in as we go along. Sounds a slow process? It is. I think we've averaged about 3 - 4mpm and in the shallows and we've also to wait on tides. With 19km to lay, it could take some time.
And being tethered to anchors means that the barge is restricted in roll in these conditions; it judders and shakes instead. Some nights you think the whole thing is coming apart around you and the chances of sleeping are virtually nil for the unseasoned matelot. And then suddenly it stops rattling and clanging which also makes you sit up! The good thing is that we're operating in only around 8m of water so if it all goes to pudding, I'm either in my cabin on the 6th deck (87 steps to climb) or in our mission control on the second storey of a stack of containers, so I won't even get my feet wet.
The lowering into the sea of the trencher was a very carefully controlled operation lasting some hours. The cable we're laying is on the left, the umbilical which incorporates all the control systems and hydraulics for the tool is in the middle and the massive hoses on the right carry the water that in conjunction with the cutting tool, clears a trench - sometimes up to 8m deep - for the cable to settle into. The skids run along the sea bed and keep the structure stable. I found out also that the trench is back-filled by the action of the current and tide rather than mechanical means.
Once the 'tool' is in the water, it has to be disconnected from the crane. To do this, a basket, rather amusingly referred to as 'The Teabag' (it must have form) is manned by a couple of volunteers and swung out by an auxiliary crane to the trencher so the strops can be detached and secured. It was a good mornings work.
And whilst they were doing all the heavy lifting - so to speak - I had a quick look at eBay and up came this Riley RME chassis. It's the first time I've had a clear picture of what the layout is - this particular example was happily lacking everything I don't need - engine, bodywork, piles of spares that will only reverse my recent attempts to de-clutter. This one was built in 1954 and as production of the RME ended in 1955, it should have most of the ongoing mod's, though the steering column support looks suspicious.
The front offside rail has a bit of tin worm but the steering works and the wheels turn. And there's a blue button here and if I click on it...... oops!
So that's how that works.