Technical Talk

[f1steveuk]

Thought I should poke my nose in!! So let's get stuck in, about this copyright issue, no. sorry

These mysterious bulkheads, could they be the remains of the water tanks, fitted in order to adjust the trim when first built, but cut away in part as "NLR"?

[Renegadenemo]

The bulkheads are all part of the structure but half of them rivet straight onto the frame tubes so they're a little pointless really. I read somewhere that they're to divide the boat into watertight sections but they're only six inches deep in the middle and there's an inch gap undreneath where the corrugated inner floors go so I'm not sure what they're about in many cases. There's evidence of the original trim tanks at the rear. It seems they were fixed to the frame tubes and now the holes are blanked with rivets.

[Mike Bull]

Watertight bulkheads that don't go very high? Where have I heard that one before?

No icebergs on Coniston are there?!

[f1steveuk]

Steady Mike, you'll be suggesting next K7 had a sister ship, and it was this that really sank for insurance purposes.....................

It does seem strange, because these bulkheads aren't going to lend torsional strength, so perhaps just there in case they needed to mount bits on, fuse boxes, relays, lead ingots............

[Mike Bull]

Damn, you've uncovered the great conspiracy- that it is in fact the lesser-known Greenbird that Bill has raised and is restoring- and that Bluebird was in fact quietly scrapped years after the crash!

[Renegadenemo]

I have a letter somewhere from an engineer in Manchester that he wrote to DMC in 1966 to say that he knew how to make K7 do 400mph but he'd only reveal the secret if the boat had its name changed to 'Greenbird 400' Couldn't see that happening somehow.
And if there's a conspiracy to be had I want to know where the bloody instrument panel went! Never found a trace of it...

[StuartB]

Hello Bill/Guys found the Forum and now feel obliged to Join in. Might be a bit of a random theory but could they be there to break any free surface water surging through the boat and upsetting the apple cart. Where you get "free surface" ie water able to slosh about freely over a large area be it length ways or abeam of a craft its a common practice especially with larger vessels to rig temporary "dwarf bulkheads" the idea being not to stop the water completely and certainly allow it to drain towards any pumps in place but to stop a sudden surge which of course would have serious impact on center of balance and center of buoyancy. Before anyone points out the blinding obvious there shouldnt be that much water in the bottom of the boat but allowing say two gallons (ingested as the boat breaks onto plane) slosh around the hull would result in twenty pounds of weight able to move around the hull as it pleases Not such a good idea when planing angle and safety margins have such a narrow window. Very Geeky but worth more than a passing thought??

Stu

[Renegadenemo]

Stu,

that's a theory I'd never considered and the bulkheads would certainly work extremely well in that application as any free water would be able to move about the boat but only by bleeding through the corrugations beneath the bulkheads so the pumps would get it eventually without it being able to move fast enough to cause an upset. Hmmm - interesting...

[f1steveuk]

The baffle theory is the most likely, although I recall Ken saying that the amount of water that could get in was minimal, and was usually "shot out" as he put it, by the acceleration, but it would ba as well to stop even half a pint shooting down to the tail and building up there, although again it's unlikely K7 would take in much water whilst on plane and at speed??

I'd still drop a line to HMS Rosyth (spelling??) as Futcher's lot were desperate for a dive momento, and weren't allowed the steering wheel, so maybe they nabbed the dash?? Or, because of the impact, maybe it shattered and shot the instruments all over the place??

[Mike Bull]

A few threads have drifted off topic of late, so here's a dedicated thread for technical talk; I've started it off by merging in some posts from a previous attempt at a techie thread. Off you all go, then!