Bute Tuesday 7th August.

Tuesday morning was all a little embarrassing. The day before we’d been stranded for the want of some premium paraffin and today we were equally shipwrecked because our beautifully recreated canopy was in bits on the bottom of the loch.

Sally took some divers to where it splashed down and with the help of the drone pilots and their excellent footage they put a marker on where the drama had taken place but after several drops and squelching blindly about in soft silt they returned empty handed. It was the deepest part of the loch too – a whole 30 feet but Sal reported absolute zero visibility without a torch and almost none with one – an all too familiar scenario to us old hands of the diving world. The sediment was extremely soft and easily capable of swallowing chunks of acrylic too so for the moment we would have to just leave it down there.

It’s not as though we could mend it anyway but all the furniture, the latches and rollers, had gone with it and they were gorgeous pieces of kit made by Clever Barry and we wanted them back. Never mind – they weren’t going anywhere. We’d have to park yesterday’s disaster and build ourselves a new canopy.

When making the first one we’d done it in many parts. The canopy surface itself is 6mm vac-formed acrylic with an additional acrylic frame that we’d hand-made in several sections. There was the curved piece around the front that we’d carved and sculpted from solid to exactly fit the asymmetrical bodywork and cockpit opening and of those we had but one – but fortunately that was about the only part we got back.

A still from the GoPro footage at the moment of recovery (via Jordan Aspin)

And below, this is the same part found airlocked on the surface and quickly recovered by the safety crew.

The footage of it flying skywards shows that it left the boat largely intact then was torn apart by the wind with the sides and rear part of the frame separating in mid-air. The failure occurred at the hole in the top where the latch passes through. It was a very obvious stress raiser but there wasn’t much we could do about it except make sure all the corners were smooth and rounded so it wouldn’t fail in normal use but it was never going to stand being blasted skywards into a 120mph gale. See the blue, curved piece around the front?

We were super glad that came back as it took many, many hours to sculpt and rout that from solid acrylic and we didn’t have another one. Well, we sort of didn’t. We had our MDF prototypes that could be made to work if we waterproofed and painted them but as it happened we got the acrylic one back along with its little roller so we unpacked the spares and set about building a new canopy.

We had a spare canopy surface cut to size and still in its protective film so we sent out a call for epoxy (not that it sticks too well to acrylic) and self-tapping screws and made a start.

First of all we had to make sure it was all going to fit into the canopy rails and they are half an inch different in length. The doublers that run along the outside length of them are the originals so there’s no arguing with how long they are. We propped the parts in place for a look-see.

Then the legendary Jersey Mike produced a generator and grinder from somewhere and began carving a spare rear frame to fit the headrest plate.

Everyone took a hand to get the new canopy into shape as quickly as possible. Novie spent some time on the fine work.

Then we glued and screwed and heated with a heat gun to get the epoxy to go off that little bit quicker.

It was decided we’d best fasten this one down differently so the wind couldn’t steal it but this threw up some other problems. Like, for instance, how would the pilot effect an escape or a diver a rescue if the lid was nailed down? We had many discussions on this and decided that the safest and most reliable method was to bungee the canopy into place from the inside. Part of the cockpit drill would be to fasten it shut before starting the engine but should it need to come off again the bungees ought not be too difficult to overcome. As part of this we did two other things.

We gave the cockpit instruments and controls a proper going over in case anything had got wet or bashed about in the previous evening’s drama. We didn’t want an uncommanded extension of the brake or the fire-suppression going off mid-run so it all got checked and inhibited. And Sally also whipped off the steering wheel. She carried as part of her kit a big spanner for that very purpose in case an unconscious pilot might end up pinned in the cockpit on the wrong side of it so there was no harm in doing some extra training while we were peering in there.

It turned out to be all clean and dry and in order in there but it was good policy to make sure all the same.

And then, with the cockpit reassembled and signed off by the maintenance crew, we put the new lid on and sorted out its bungee arrangement.

It wasn’t as pretty as the one we’d arrived with but it was just as good if not better from a functional position and because it was purely for running it had no rectangular hole in the top and we took the extra precaution of drilling three, one-inch diameter vents in it on each side to let the pressure further equalise and, though the pressurisation problem persisted and occasionally lifted a corner of the canopy, this one remained firmly affixed for the duration.

It was getting on for lunchtime by the time we relaxed a little, relieved to be back with the programme. On top of our hasty canopy build we still had our multitude of other tasks to complete from checking fluid levels and making sure the boat’s on board batteries were properly topped off to placing fire extinguishers in the correct boats and making sure the radios were all charged. Lots to do.

Not only had the crew settled into their individual roles but the families had also set up their own little camp on the outside of the boathouse and occasionally they would augment our standard rations by firing up a few disposable barbecues and cooking an extra treat for us.

Now to say that the Isle of Bute fully embraced the Bluebird Project and all that came with it would be an understatement but we thought they’d lost the plot completely when we heard we could buy genuine Bluebird sausages in Rothesay. Now this we just had to see.

If you found this in your fridge you’d likely throw it out then throw the fridge after it.

But within that slightly off-putting blueness was a feast of good, wholesome sausages and they tasted amazing.

We scoffed the first lot then went to get another batch but they’d sold out and soon after we stopped barbecuing altogether because every time we lit a fire some nutter became convinced that we were going to blow up the whole island so it weas easier to not bother than to explain. The problem was that they could see proper steel drums of paraffin alongside the boathouse correctly marked up with the relevant stickers and beyond that we had all the paperwork on file but in the foreground they could also see a barbecue and in their fevered minds this simple source of ignition was going to magically leap the thirty foot gap and set off an explosion in the oxygen-free, tightly sealed drums that would roast us all to a crisp because, as everyone knows, jetfuel is malevolent volatile stuff that will suck in a mouthful of barbecue at the least provocation and explode in your face just out of spite. It was easier to eat cakes.

We had a visit that morning too from our old mate David Tremayne, author of Man Behind The Mask, amongst many other titles. We’d done a few little jobs on his jet car the year before so he came up to see what was going on with the big tin machine. It was great to have him take time from his hectic schedule in the world of F1 to come see us.

Now back on track with a functional boat we got down to what we were supposed to be doing and that was to get Stew out there for a slow taxi and, if we had time, strap Ted in to try out the new canopy arrangement at speed, though what we were going to do if another canopy went skywards no one wanted to think about.

This was to be Stew’s first time afloat so he was anxious to learn as much as possible from hydroplane ace, Ted. They discussed many things including the best bungees to keep the cover over their heads.

And then, as Stew usually did, he found some peace to do his methodical, RAF pilot thing and set out what he needed in detail on his laptop.

We speculated on what might be were the roles reversed. What if Ted was about to be handed Stew’s Red Arrows Hawk? The consensus was that he wouldn’t read the manual, he’d just strap in, jam the throttle wide and blast up into the sky. We’d then all witness a few heart-stopping moments as he reared and bucked around the stops before it all smoothed out and he’d land safely wearing that big grin of his.

John topped off the start bottles…

Rich prepared the safety boat and rounded up the crew…

Then we rolled out ready for action.

Malcolm called the safety brief.

It was an especially thorough affair this time considering yesterday’s mishap, the resulting repairs and necessary changes to our procedures not to mention the fact that we were putting a new pilot in the cockpit this time. We religiously observed that there was no time pressure at these gatherings and it would take just as long as it took and not until Malcom gave the go ahead would anyone do anything.

Stew kitted into his smart black flight suit and looked on a little nervously.

But with everyone happy and the machinery and team good to go the smile soon returned and we got on with launching him.

We were by now confident to launch with the pilot already installed. It made no difference to the launch whilst conferring several advantages to the pilot, not least being the unlikelihood of him falling into the loch when transferring from the safety boat. We got our precious cargo afloat and fussed (yes, that is supposed to say ‘fussed’) about in the usual way making sure that everything was just-so before attempting a light.

We’d double checked the igniter circuitry during the earlier maintenance visit and it would have been a cruel blow to have another failure as all had been working right up until the point of launch.

The drill was becoming well practiced by now and the engine lit exactly as expected. It whistled up to the usual, annoying 45% and Stew was underway rather more quickly than we would have liked but he seemed perfectly composed and in control in there.

The brief was no planing and only go as far as the narrows where Jordan, Rich and Sal were stationed. We knew the speed fell off very quickly on a closed throttle when the boat remained mostly in her displacement condition but it was still a very impressive sight. Stew followed his mission profile to the letter, performed a smooth turn at the narrows then came back a little faster but still quite deep in the water.

In Stew’s own words…

*

With K7 float tested and having completed engine runs on the edge of Loch Fad there was nothing else for it, the time had come to start her on the water and see how she handled at slow speed. With his vast experience on water, the decision was made that Ted would always be a run or two ahead throughout the trials which would minimise the chances of an unexpected surprise for me. However, even with this comfort blanket, I still felt a significant amount of trepidation every time I climbed into Bluebird’s cramped cockpit and strapped in.

I will never forget that first run.

The sun shone and the beauty of Loch Fad with the mountains of Arran so clearly visible at the south western end perfectly framed what were to be some of the most memorable minutes of my life. Initially, in near silence, K7 was carefully towed from the shallows to a suitable start point. The experience inside the cockpit was intense. There was no getting away from what a privileged position I was in. Looking around the perfectly restored cockpit it was impossible to not think of Donald Campbell sat there over 50 years prior and contemplating what he was feeling as he prepared to push the craft to world record breaking speeds. Those speeds were not on the agenda for me, thankfully. Yet, before I even turned the Orpheus engine, she felt so capable of incredible speed. Her blue sponsons seemed to naturally narrow the focus from the cockpit and indicate exactly where she wanted to go - straight and fast!

My moment of reflection was broken when I caught a glimpse of Bill’s huge smile coming from Jimmy’s launch boat. We were in position and ready to go, everything was set. I closed the canopy which made the cockpit even more cramped; at 6’1” I was significantly taller than Campbell. It felt just like starting a jet aircraft. I followed a check list I had prepared which was based on the drills used to operate RAF aircraft. I gave the hand signal to the launch boat and the silence was shattered. High pressure air from tanks on the launch boat turned K7s engine over, she kicked into life with the flick of a few cockpit switches and within seconds we were underway. I had prepared myself to have very little directional control at slow speed due to her small single rudder but was presently surprised when she responded almost instantly to my directional inputs. That was the first big relief, I was underway and had directional control. The thought of grounding her or hitting an obstacle had been at the forefront of my thoughts and concerns.

With control assured and the start boat safely disconnected, my nerves quickly faded and I couldn’t help but marvel at what I was doing. K7 was under her own steam in near perfect conditions and watching were hundreds of enthusiasts from the shore. It was a special moment and I couldn’t help but smile as I took her approximately a third down the loch and back again. Apart from the occasional splash lapping up around the cockpit, it was hard to not feel like I was taxiing a jet aircraft. The noise was of course the same, the response of the engine similar and the gentle manoeuvres I made were akin to the turns made heading out to a runway. Several times I advanced the [pedal] throttle to assess the response and control. After the usual delay of a jet engine spool up, the thrust was evident and significant. As the power came on, K7 tracked straight and slowly lifted as she made her way towards the ‘plane’. Retarding the throttle she gently lowered.

K7 felt incredibly stable and controllable. The slow speed run was a resounding success during which the temptation was there to keep the throttle planted and see what she could do. However, this was not the purpose of the run nor any of the trials on Bute. We were there to test that she had been restored to working order and if I could safely get her to ‘plane, that would be mission success. With the slow speed runs now complete, it was time to up the pace and see if she would.

*

It was a perfect run and everything worked and we all agreed that Stew had been more than a bit brave to accept his mission and see it through. Needless to say, he was a happy (and probably a little relieved) camper as we towed him in and we welcomed everyone ashore.

We had elected not to recover with the pilot on board this time despite having done it the night before with Ted but that was because we were losing daylight and didn’t want to delay things so we dropped Stew on the pontoon from the safety boat – he seemed most pleased.

There was much congratulation and hand shaking and, as ever, our fighter pilot was a hit with the ladies but we still had business to attend to.

We had our safety debrief with Malcolm – no getting out of that one no matter how smoothly things went – and Stew had to be thoroughly debriefed individually so we could record things like maximum jetpipe temperature and make notes on handling, wind effects and many other parameters. The recovery crew soon had the boat back ashore and immediately the maintenance team set-to topping up the fuel and other fluids and getting the water out. It was still getting in at a rate that really concerned us because we couldn’t work out how. It wasn’t getting any worse but it wasn’t getting any better either.

We had a meeting and decided we had just about enough daylight remaining to run the next part of our plan and get Ted out again to try out the new canopy at speed.

We had time for a cup of tea and a natter then Malcolm called the register and we attended his safety brief for the second time that day. This was to be a re-run of yesterday but hopefully without the canopy issue followed by a slow turn at the top of the loch and a return run on the plane so we could all get a look at the boat coming towards us under power because only the safety boat crew and a handful of keen hikers had actually seen that up to now. We loaded Ted up.

Notice the vent holes in the lower corners of the new canopy. Designed to let the cabin pressure blow out to the outside when the engine spooled down, we later wondered if they were ineffective by being trapped right down in the corner with the spray baffle on the other side whilst trying to vent into an area of high pressure air immediately ahead of the inlets. They certainly didn’t cure the problem in the way we’d envisaged but at least the canopy stayed down – mostly.

Ted was rolled into the water aboard his steed and we prepared for our second run of the day.

We ran the launch, start and release procedure like a well-oiled machine this time and Ted was underway in no time. He takes up the tale from within his office.

*

Let’s go with the Air start and general procedure... I’m not a complete stranger to high-pressure air so I know that its bad when it gets out of hand but filling up the original HP spheres to 230 bar must of required a matching pair from the operator along with some confidence in the clobber. Knowing that all that energy is held back by a tiny little valve the size of a matchbox doesn't half focus the mind on what’s going to happen when you press the button and what all that air mixed with 56 gallons of premium kero is going to do to your head if it all goes wrong At least in the Vulcan the kit was some way from the operators and even in XM691 there was something greater than the flimsy panel and the kero twixt them so it’s with some trepidation that once you have the various valves and switches turned on you press starter and unleash what sounds like 10,000 very pi55ed off hissing vipers down the pipework to get things spinning. There is a good bang and off she goes.

On Bute we were using a hybrid air start system comprising two large 50 litre cylinders and an off board trigger so, from the top, following on from a few 'duds' in Bute, before I close the canopy I flip the hidden ‘Master’ switch behind the dash panel to 'on' and have a good listen for the igniters. I should be able to hear them crackling or fizzing away. They are different to the cracker-box style used on later engines. I do this now as once the canopy is shut you can’t really hear them. I call "igniters" to the start crew just for the extra confidence, they can hear them also.

If we are good we leave them on, and on with the show but if things are not working then it’s a one hour wait to recover, remove the engine cover and its gazillion screws but at least save the precious air rather than loosing 1200 psi with a no-light and subsequent potential hot-start with all that un-burned kero swilling around in the engine. Check the yellow engine blanks are removed and close the canopy making sure the so ‘n’ so of a thing is well engaged and tied down with the extra bungees we added after the first one failed to stay in place. Turn on the fuel (Low Pressure LP Fuel), this is the black 'T' handle above the Bloctube control, by pushing it in towards the bulkhead. It operates a simple tap in the bottom of the L-shaped secondary fuel tank and is the last line of defence if things were ever to go wrong with the throttle quadrant return, though it was a procedure we were yet to test. Next up is the Bloctube control. This works though a complicated set of push-pull rod linkages back to the turbine fuel control system. Some folks like to call it HP or High Pressure fuel I can't be bothered with such nonsense, to me it’s 'Engine to Idle – Engine off ' as that what it does by setting the quadrant on the bottom of the Fuel Control System to 30 degrees of opening or 0 degrees accordingly. Then it’s on with the boost pumps, strictly speaking they are submerged electric fuel pumps to get fuel to the turbine’s 'real' fuel pump, a multi piston pump with sooo much clever stuff going on inside it really is a triumph of 50's analogue engineering, but the electric ones ultimately help keep the piston pump supplied with a good flow of kero...or do they? So at this point we are hot and ready to go. Reach over the dash to the start switches on the left hand side and with the right hand give three 'Wikid' fingers, Agincourt and Bird to the control boat in view of the cockpit, listen for the count and at the appropriate time, which is any time after "One" hold down the push button and depress the toggle switch with a spare finger to unleash better than 1100 psi into the Rotax start turbine... Now, on modern turbine that would be it, electrickery would sort out all the what if's whens and wherefores and hand it back to you running or in need of maintenance but there is still a fair bit of work to do on ours, namely THE JPT. The Jet Pipe Temperature indicator is the,

'Oh my, I’m going to get a serious talking to from the Chief', gauge.

Too much fuel in the turbine and it’s an aborted start? That'll be a hot start. Not enough air in the start system? Hot Start, sir... Taking your finger off the starter too early? Hot start. Start boat disconnecting your air too early? HOT START, you’re getting the idea here…

The dreaded condition can to lead to the excess heat changing the make-up of the blades in the turbine thus allowing them to disconnect from their previously cosy home and spear through the super light alloy casing maiming all the young children, nuns, assembled dignitaries and the Wonder Woman /Xena warrior princess lookalike competition entrants following Bluebird pilots to become the proud owners of, albeit for a short time, red hot shards of metal from inside the once fully functional 'tube of blades'. From the pilots briefing perspective it was along the line of.

"There are only four of these feckers left in the world that still work, Dont blow one up!"

OK! No hot starts, got it, right on. Now we know with our 100 litres of air and our low pressure starter we get three good starts and also that it takes an eternity, well at least all morning, to refill the spare pair of cylinders we decant from so we don’t like wasting air really for any reason so, personally, I don’t want to be on the button for any longer than possible. This means getting out of the starter as early as possible without causing a JPT spike to ruin the day. I mean after all, I like those Xena outfits, all that leather and fur, I digress...But on Bute I learned I could predict the likely JPT max by knowing how much air I had available to start with. 2400 psi meant a cracker, JPT topped out at 670 degrees 1800psi 700 degrees. Even though the pressure to the turbine was regulated it was good to know as watching the JPT with one hand on the starter and the other on the Bloctube is that needle climbs real fast towards the shut me down danger lever of 720 degrees.... but you don’t wanna pull the fuel and waste the air unless you really have to, but once I understood it we were OK ‘cause those last 5 ticks on the gauge go past all to quickly before returning just as smartly to permitted levels where the Queen of the Amazons is safe at last. So it’s all good. Get your finger in, BANG, HISS, WHOOSH, WHINE, count one two three, I should hear the burners fire now, four five six seven, wait for 300 on the JPT, starter off. Climbing temps now but had plenty of air so expect sub 700 JPT max and there the needle is back to 650, engine a revvin’ so thanks and away?

Er, no... We learned quickly that for whatever reason the trigger valve on the start-cart can sick open and allow the start turbine to overspeed leading to Xena-threatening situations. That along with damp from the lake freezing as all that rapidly expanding air as it removes the heat from the feed pipes and prevents the start team from breaking the coupling while I happily chug off oblivious to the inconvenience of two 50 litre air cylinders, a fishing boat, two extra unexpected passengers and the remainder of at least 1200 psi's worth of air still firmly attached to the side of our iconic craft because of an iced up coupling, so once things look promising it is hands off the switches to show control we are out of the starter. They indicate to the start boat to get on with it and once the boys are all disconnected they give the dive sign 'OK' on the fingers to the pilot meaning proceed (rather than the thumbs up which means 'go up' to the divers on the team.) Needless to say, with it all working you go to the next set of near-death / boat-wrecking tasks we had detailed ourselves with for that particular run...

*

Ted had the measure of the boat by now and wasted no time in straightening up on course, getting settled then nailing the throttle. K7 howled and flung herself headlong into a whirlwind of spray in which she became completely invisible until after only a few moments she emerged going like a scalded cat.

At this point, Ted reported no visibility from the cockpit so it was important to be facing in the desired direction when nailing the throttle until the wind outside blew the water away and turned zero visibility into merely not very good visibility. K7 accelerated like a rocket and was soon thundering up the loch absolutely true and steady.

One shot that was captured time and again was Bluebird passing Keane’s Cottage – a holiday rental owned by the Mount Stuart estate and very nice too as both a destination and a backdrop.

(Pic Courtesy of Paul Simpson © 2018)

Our plans to come to Bute were fairly advanced by the time someone realised that the holidaymakers who’d booked the place for the two weeks we were on site were going to have a jet hydroplane whizzing past the bottom of their garden on a regular basis and if they’d come to find peace and tranquillity this could be a problem. And it got worse, because it was let to two separate groups for the two weeks so our potential to upset someone had either doubled or halved in one go. Better tell them what’s happening, said the lady from Mount Stuart. That caused a chuckle – better tell them.

After being subjected to years of committees and consultations and all the other instruments of inefficiency that mankind has inflicted on his ability to get anything done the idea of just telling someone was a breath of fresh air and judging by the number of people who strolled down from Keane’s Cottage for a look it seemed to have worked out OK.

Bluebird, with Ted at the helm, streaked past then began to decelerate just after the narrows.

One thing we’d long pondered was the cause of her oft-reported ‘tramping’, a phenomenon in which she would violently dance from one sponson to the other with sufficient force and frequency to rattle the eyeballs. We decided a long time ago that the cause was simply a result of her cockeyed construction with the result that the sponsons fought for equilibrium at about 80mph but we were interested to see whether it happened to us.

Our sponsons were accurate to +/-1mm over 12 feet (apologies (well, not really) for the mix of units) and the geometry of the spars and sponsons was set up to three decimal places using 3D laser scanning so we knew we hadn’t built anything cockeyed and, lo and behold, no tramping. Just very smooth acceleration right through the relevant speeds with no fuss or drama so that’s one feature of K7 we didn’t accurately recreate and nor did we care in the least.

But where had she gone?

From the safety boat position to the rear and having to listen through the spray, the engine became inaudible fairly quickly. Later we’d find that it was only when a turn was initiated that a low, echoing rumble could be made out on the breeze if it happened to be blowing the right way but this time there was nothing. Bluebird had flamed out at the end of the run so that would be that for the day. We towed her home.

Ted was in fine form as we brought him ashore – this time in the cockpit as we reckoned we were happy recovering with him on board by now.

Stew came down to share some pics and video. It had been an excellent run but why had we lost the engine?

We had a good old debrief about it and the problem was ultimately revealed to be both a simple but very significant one.

When the boat was re-engined in 66 they left all the throttle linkages exactly as they were and only modified the very last linkage to throttle up an Orph’ rather then a Beryl.

Now we had rebuilt it all in exacting detail right down to having the springs tested and perfect replicas made so it was identical in both operation and feel to what Donald had beneath his hands and feet in 66.

Clever Barry did likewise when he built the new ‘Bloctube’ control box for us so even the springs in the detents inside there are the same – such was our obsessive attention to detail.

That black box is a copy, though the red Dymo labels were made on Donald’s old machine that Gina brought up for us to use with the last of his original red tape still inserted all those years later so that’s fairly authentic.

What that box does is open the throttle valve on the engine 34 degrees for start and idle and holds it there on a detent. (The little black handle above it is the LP fuel cock).

The remaining 56 degrees of throttle travel is controlled using the foot pedal and it all worked as intended but in building it so accurately we unmasked yet another gotcha and one which very likely caused the flameout on Donald’s first run on the 4th January 1967.

On Ted’s run down the loch, Bluebird had behaved impeccably but as he approached the far end the cockpit was suddenly illuminated by the low oil pressure warning. Amongst the cacophony it was the first indication that something had gone wrong but Ted worked out straight away that on coming out of the throttle the return springs had overcome the detents in the Bloctube control and shut the engine down and by this point it had insufficient energy to recover even if the valve was reopened.

We’d not had this when testing back at HQ because the linkage was new and stiff but by now it had been cycled a few times and the grease was bedding into the bearings and when we experimented after this latest run we discovered that unless the foot throttle was eased off with the utmost care and gentleness its return spring would simply pull the Bloctube lever out of its detent and shut the engine down.

Imagine screaming through the measured kilo on that freezing January morning, your linkages having had some time to bed in and free off. Then you thump down the water brake and, amongst the speed and drama, come out of the throttle ever so gently – not.

It’s entirely possible that what happened to us on Bute is exactly what happened that morning on Coniston Water and with a dead engine at 300mph and warning lights in the cockpit there was no choice but to blow off the remaining starting air to get it going again or that was the record bid finished for the day.

But the resulting trade-off was that with no starting air there could be no refuelling stop or a decent enough amount of time to let the lake settle down before the return run as the engine was steadily drinking what fuel it had left.

The realisation is all a little ominous…

Later investigations would reveal that the actual throttle valve on the Beryl engine is very different with a longer throw on its lever and much greater resistance hence the requirement for such a hefty control.

(Beryl Throttle Lever via Fiona McDonald 2019)

Above is the Orph’ CCU (Combined Control Unit – basically the engine’s carburettor) and on its left upper face in the foreground you can see a short lever with a brass quadrant attached at its base with two shiny nuts and marked off in degrees.

That lever is only 2 inches long rather than the 4-inch equivalent on the Beryl and a good breeze can blow it around – such is the difference to the industrial kit on the Beryl.

Fact of the matter is that the Orph setup is so much lighter in its operation that the springs suited to the Beryl are just too strong for it and easily overcome the detents in the Bloctube control – who could have seen that one coming?

We were told by the HLF ‘experts’ (none of whom ever visited the boat) that if we took all this apart we’d be ‘destroying history’. And yet, by taking everything apart then working out how to put it all together again what we actually did was unearth so many small snippets of history that, without our efforts, would unquestionably be totally lost by now.

Anyway – we digress… The throttle spring question now presented an interesting conundrum for us too because, with no on-board starting, we had to take the start boat alongside every time, which meant if we lost the engine at the far end it was a major operation to traipse up there not to mention it being more or less out of radio range from Malcolm and so it was easier to recover by towing after those early runs.

We discussed all sorts of options to cure this at the side of the loch but in the end they all led to increased difficulty in shutting the engine down in an emergency should the need arise so one by one they were rejected leaving us with nothing more imaginative than telling the pilots to keep one hand on the lever when decelerating. We’d just have to see if that was going to work but for now it was time to start gathering in the back room of the Bull for the real debrief.

Tomorrow we’d see if Stew could put in a fast run and maybe even a return run too if we could keep the engine lit.

We’d come to Bute to train ourselves and further develop our newly rebuilt machine and though we had thus far made great strides there wasn’t at this stage any sign of us getting ahead. The more we learned the more, it seemed, we had yet to work out but we were getting there.