So, what did Bluebird sound like?

[KW Mitchell]

I was privileged to hear K7 in late 1966 and can confirm Keith Mitchell's observations and assertions. The first day I heard it was from a distance of several miles, when staying at the Tarn Hows hotel and I can still remember clearly it's note echoing off the hills early on that first morning. At close quarters it was truly awesome and I can still recall the excitement as K7's engine spooled up with the boat lying low in the water before planing and then -whoof!, she would get up on the plane and accelerate away unbelievably quickly, trailing the characteristic rooster tail of spray and accompanied by the unique sound of the Orpheus. It was absolutely stunning and no less exciting each time I experienced it.

I would give my back teeth for memories like that, Rob. Can you say which particular runs you witnessed?

[rob565uk]

The memories are still vivid and are certainly treasured, Keith. I was only 14 years old at the time and unfortunately have no diary from that period, but from conversations with the Uncle who took me up there, I think the runs I witnessed were almost certainly those of the 12 -14 December 1966 timeframe. To my young eyes, K7 looked very fast indeed and I can remember more knowledgeable observers commenting that she looked ready for the record.

[KW Mitchell]

The memories are still vivid and are certainly treasured, Keith. I was only 14 years old at the time and unfortunately have no diary from that period, but from conversations with the Uncle who took me up there, I think the runs I witnessed were almost certainly those of the 12 -14 December 1966 timeframe. To my young eyes, K7 looked very fast indeed and I can remember more knowledgeable observers commenting that she looked ready for the record.

Thanks, Rob. As Mike says, 13th Dec. - intriguing given DC's anathema of anything smacking of ill-fortune! The average of the two runs was 264.5mph and he was disappointed as it was below his existing record. He again complained of fuel flow limitations (ain't this a recurring theme throughout the saga -------!) and the BS engineers were again called in on the 14th.

I know this might be too much to ask of a 14yr old's recollections, but was the roar & whine of the Orpheus interrupted by a rapid and very low loud 'parp-parp-parp' (a bit like machine gun fire), particularly during the acceleration phase up to planing?

I very much suspect not - as no authoritative account mentions it - but it would be interesting to hear from someone who was there.

The phenomenon I am describing here is 'surging' - a problem in jet engine operation when the compressor blades stall, particularly during heavy acceleration, see earlier thread:

http://www.bluebirdproject.com/message/ ... g&start=40

The reason why I am interested is in relation to the intakes of K7 where BS recommended some modifications following the collapsed duct incident earlier in the campaign. I can't find any evidence that these were done. If they weren't there would have been complications under certain running conditions (I don't know whether there are any living observers of the static runs done during the period as this would have precipitated potential engine 'surging' ---------------?).

As I say, I don't think the phenomenon occurred (surging produces an unbelievable racket which would have been obvious to all and sundry) but it would be nice to eliminate it completely.

[KW Mitchell]

Apparently this was December 13th-

1966 13th december 01.jpg

Let's take a closer look at that photo' (I've att. a version with brightness/contrast enhanced to show more detail).

Note that trim appears perfect and that BB is running on virtually a pristine water surface (this agrees with Arthur Knowles' account of the running conditions on that day).

More importantly, note that almost half of the stabilising fins are evident indicating that the hydrodynamic lift being produced is due to them and not the planing surfaces which are in free air.

Now, have a look at the penultimate run on Jan 4th see previous thread:

http://www.bluebirdproject.com/message/ ... 0&start=90

In my view it confirms the contention that BB was operating at marginal stability - even in perfect running conditions - throughout that final episode and not just on the final run of Jan 4th ----------.

[rob565uk]

Keith -regarding the noise associated with surging - to the best of my recollection I heard no such noise.

[rob565uk]

Static Tests of K7 in 1966/7: There is some coverage of static engine testing in the "Price of a Record" documentary film by John Pett. There is no sound of surging, but it's not clear whether the tests are pre or post intake re-build.

[KW Mitchell]

Static Tests of K7 in 1966/7: There is some coverage of static engine testing in the "Price of a Record" documentary film by John Pett. There is no sound of surging, but it's not clear whether the tests are pre or post intake re-build.

Where might one get a copy of this (video, I presume?), Rob?
K.

[f1steveuk]

There's two versions of Price Of a Record. The original to my mind is the better one. The latter is the same with some additions by Melvyn Bragg and i/vs with Gina. Very atmospheric record of 66/67. Then there's Challenge of The Lake, nice colour record of the Lake Mead attempt, though typically American and "of it's time". Where would you get a copy? Well mine were lent out and never came back, but Colin Cobb was always a good source of BB footage!!

[rob565uk]

Have never seen 'Price of a Record', am I missing something good?

Mike - I was given a VHS copy of the original many years ago and it started to deteriorate, so I copied it to DVD and made a backup. I will bring the backup to the workshop when I visit on Saturday. You are welcome to borrow this and pass it on to Keith Mitchell for his use when you have finished.

[rob565uk]

Static Tests of K7 in 1966/7: There is some coverage of static engine testing in the "Price of a Record" documentary film by John Pett. There is no sound of surging, but it's not clear whether the tests are pre or post intake re-build.

Where might one get a copy of this (video, I presume?), Rob?
K.

Keith - I have sent you a PM re this