From wreck to racer: The inside story of Thunderstreak’s remarkable restoration

This is the story of Thunderstreak, the late Tommy Sopwith’s 1963 Bertram 31 Competition Special, and its three-year restoration. It’s also a story of dedicated powerboat people and skilled marine engineers with the determination to succeed against all the odds.

My tale, however, starts on August Bank Holiday 1963. To this then 13-year-old, that meant one thing: it was the Daily Express Cowes-Torquay powerboat race weekend. Spectating at this new and exciting sport had been getting more dramatic every year.

Top speeds had reached 50mph. Engines had got bigger. And louder. Striking, purpose-built raceboats had begun to fill the entry lists – many from the USA and carrying the Bertram brand.

The sight of 50 starters lapping the Isle of Wight at full-chat then powering on to Torquay was unforgettable.

As the now stretched-out fleet blasted past Cowes for the second time, the visceral bellow of Thunderstreak’s 7-litre Holman-Moody tuned Ford race-engines as it porpoised past trailing a rooster-tail behind it made a lasting impression on my teenage mind. It was love at first sight: or perhaps love at first sound.

Thunderstreak was discovered by Robin Ward as a dilapidated houseboat

Never, for one moment, did I dream that one day I would own her. Fast forward to late summer 2017 and across the River Medina I detected the familiar rumble of just such a pair of V8s. It turned out to be Thunderstreak, sporting her H400 race number.

Then in the ownership of Robin Ward, who discovered her in 2014 as a rotting houseboat in an East London marina, he had completed an initial restoration and raced her with mixed results in 2015 and 2016. It took one chat, one test run, and one offer to become the owner of this historic vessel. Now the hard graft would begin.

Labours of Hercules

The Bertram came ashore at Clarence Yard, East Cowes looking rather the worse for wear: weedy bottom, asthmatic engines, scruffy internals, corroded ancillaries, tired sterngear, dated electronics – you get the picture. Solent Marine Services (SMS), led by partners Tristan Ormiston and Jim Willcock, agreed to take on the challenge. With the help of Peter Hewitt, my skipper and restoration project manager, we scheduled a plan of works over the winter of 2017 with the aim to race again in 2018.

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First, out came H400’s engines. They were in a horrible state – burnt-out cylinder heads and ill-seated valves, scored bores and piston-tops, worn engine blocks with clogged water galleries. We also extracted the original Velvet-Drive gearboxes and Precision-Glide V-drives. The engines were shipped off to Saunders Engineering at Cadnam, where several of Tommy’s old race engineers still work, for balancing and assessment.

The gearboxes and V-drives went to Mike Bellamy’s Lancing Marine to be assessed. Meanwhile SMS set to work on the rudders, steering gear, P-brackets, hydraulic trims tabs, stern glands and shafts, all of which needed overhauling or replacing. Meanwhile, the yard arranged for the hull and topsides to be given an Awlgrip finish, in Tommy Sopwith’s Endeavour Team colours of dark blue, red and white, for which he had given me his kind permission.

Express Signs Ltd of Newport provided new boat graphics, race numbers and Union flags – again sanctioned by Tommy. For clarity, the ‘H’ prefix indicates the class in which she will race – namely, ‘Historic’, not ‘Hugo’ as some wit suggested. All the original brass hull outlets and seacocks were replaced by new or stainless ones. New water-cooled sternglands, bilge and fuel pumps, wiring, switchgear, dashboards, and high-capacity filters were plumbed in. And any suspect old GRP repairs were hacked back and re-glassed.

The engine bay was a mishmash of rotten timbers and hidden repairs that was only fully revealed once the engines were removed

At the same time, SMS went shopping. In Yorkshire, they traced a spare Ford V8 engine from a campervan. From America, they ordered sets of new pistons, piston rings, gudgeon pins, con-rods and big-ends, hydraulic rockers, cylinder sleeves, four shiny rocker covers, plus belts, pulleys, filters, pumps, exhaust headers, hoses, clips, wiring and electronics. This extensive list was slow to materialise and meant that the rebuild wasn’t finished in time for the 2018 Cowes-Torquay-Cowes race. Nonetheless, the engines eventually came back from dyno-testing at Bicester that November and all was set for the new H400’s maiden voyage.

All went well right up until the point when one of her immaculately restored engines blew. An investigation suggested that at some stage (we don’t know when) its internals had been run dry and was now beyond economic repair.

Back to square one

The SMS team, Peter Hewitt and I all went home for Christmas deeply despondent. Early in the New Year of 2019, I called a team meeting and laid out the three options open to us: junk the whole project; rebuild the Ford engines again or replace the existing motors with state-of-the-art new ones, possibly with racing sterndrives in place of the original shafts.

The Holman-Moody race-tuned 7-litre Ford V8s were stripped and rebuilt only for disaster to strike on her maiden voyage

This third option, while not fully embracing the restoration purist’s approach, opened up three further choices. The first was to install Volvo-Penta’s 6.2-litre V8 petrol engines with Duo-prop sterndrives. This would give 430hp each side and the best power-to-weight ratio. But the absence of through-transom exhausts removed the critical sound element. I mean, who wants a silent AC Cobra?

The second was to use Swaymar Marine’s small-block race-tuned 6.5-litre V8 Chevrolets but employing the original gearboxes and V-drives. Although boasting race pistons, rings and big ends, and a fancy ‘bunch of bananas’ stainless exhaust system from Australia, these beautiful lightweight units only came with carburettors, not the more efficient fuel-injection system. And no proper warranty package.

The third option was the latest fuel-injected 8.2-litre Mercruiser engines with Bravo X sterndrives. In supercharged full US race-tune, these are capable of 1,650hp but we were looking at the under-stressed naturally aspirated 435hp models. While they would provide good reliability, at 589kg each they carried a 150kg weight penalty per unit over the Volvos. But they had straight-through exhausts and comprehensive warranties on the engine, leg and ancillaries. The downside was that H400’s transom and half her internals would have to be rebuilt to accommodate the sterndrive legs after 55 years of shafts and V-drives.

As she looked after her initial restoration by Robin Ward in 2015

After much debate we opted for the latter and with the threat of disembowelment for failure hanging over the team, a new spirit of optimism pervaded the yard! I drew up a sensible schedule and ordered the Mercurys.

The rebuild begins

The rebuild would be a major task and needed professional input from a naval architect. So I contacted H400’s original designers, Ray Hunt Design, for advice and enlisted the Lymington-based raceboat designer Adam Younger to measure up the stern half of H400 and pen the necessary structures to carry our bigger, heavier engines. With all this to hand (and my chequebook!) the SMS team set to work.

SMS engineering director Jim Willcock left me in no doubt about the challenges we faced: “With almost 1,000hp to manage, the mechanical stresses are huge and racing multiplies these 100-fold. We measured everything several dozen times; set up our templates with string and wooden dummies, took a deep breath and cut open the transom.”

Measuring up one of the new Mercruiser 8.2-litre V8s to see where the sterndrives should sit

By now it was June 2019 and the C-T-C race was only three months away. H400’s stern looked like a bomb had hit it. The engines were delayed by customs and I was getting frantic. SMS went into overdrive. “We had already completely gutted the internals, by March,” continues Willcock, “cutting back old stringers and obsolete engine mounts, removing the original V-drive pads, sternglands, shafts and the old 900-litre fuel tank. We even discovered another fuel tank built into the hull!”

Tristan Ormiston, the throttle-man on fellow C-T-C raceboat Mr Noisy, advised that the new design would give a much lower centre of gravity for racing, saying, “The trick is to get the engines as low and as close to the centreline as possible without them actually touching and still enable access to key parts where they ‘kiss’.”

SMS’s challenge was to remodel the entire aft third of the boat to take the new engines and sterndrives. This entailed serious risks. The frighteningly thin original GRP transom was stripped back and six old exhaust holes plugged. The plan was to create two new transom pads to carry the Mercruiser drives and brackets, both of which had to be squared exactly.

Building out the reinforced transom to create a perfectly flat mounting surface for the drives

SMS used traditional methods of string, tape and ruler for the datum mark-up to establish the all-important ‘X-Line’ – an imaginary line following the engine’s crankshaft centre to the top of the sterndrive where its gearbox resides. These pads were made up from bonded layers of 10mm and 12mm marine ply held in position by layers of GRP.

With these pads in place, SMS turned to the engine bay, which they reinforced with bonded layers of marine ply scarfed and glued round the pads and then tied into the hull, topsides and deck. The transom also received four massive new knees, which extended forward to join the new bigger stringers, which also doubled as engine beds.

These extended around a new 875-litre aluminium-alloy fuel tank to rejoin the original 1963 stingers roughly amidships. The transom then had to be rubbed down and coated with a hi-epoxy primer and PeelPly to leave a smooth pre-painting surface for the final two coats of Awlgrip Topcoat.

The two main stringers and engine bearers were extended around the fuel tank

It was a stressful July, as SMS plotted routes for the fuel lines, bilge pumps, hydraulic pipes, wiring looms, fire-suppression systems and steering tie-bars, along with new scrutineering-proof battery boxes. High-capacity fuel filters and industrial extraction fans for the new engine box were also fitted to suck out petrol vapour from the bilges and reduce the risk of starting the engines with a bigger bang than intended! It was all starting to come together but time was moving on and the race was getting closer. As Peter Hewitt recalls, “Barrus commissioned the engines and breathed life into H400: Hugo breathed again, too!”

In August 2019, Thunderstreak was relaunched in her new 21st century iteration – a legend rekindled through state-of-the-art Mercruiser engines, race-propellers and competition sterndrives. She fired up first time and in her sea trials off Gurnard, even with mismatched props, she topped 57mph.

Like many Bertrams, she rode nose-up so we returned to the yard to fit 350-400kg of ballast (builder’s sand and gravel) in the bows to balance the weight of the new drivetrains. Thank heavens for B&Q! Frenzied last-minute jobs included assembling the kit required to race and on the day before race day Thunderstreak passed the official scrutineering process with flying colours.

H400’s long-suffering owner Hugo Peel (left) shares a laugh with skipper Peter Hewitt

With Robin Ward as race co-driver, we took one last test run on the newly matched bigger props. Disaster! Off Newtown Creek, one engine stopped dead. We soon diagnosed fuel starvation but not the cause of it. We spent the next four hours ripping up floorboards and stripping down the fuel lines, filters and pumps to find the culprit.

Nothing. A total mystery. And for the second year running we had to withdraw from the race. H400 spent a long, lonely night in the Royal Yacht Squadron Haven. The whole team was devastated. Only later did we discover the culprit, pea-sized blobs of silicone sealant lodged in the fuel cock.

Spirits rise

Come the autumn, sea trials recommenced using new equipment, electronics and different props. Barrus had provided us with two ‘pairs’ of stainless steel race props for testing. These gave us around 60mph but we were short of 350rpm on the port engine for reasons no one could fathom. With the props off, closer inspection revealed that while they showed correct and complementary part numbers, they were not a perfectly matched pair.

All sorted and ready to go with new racing sterndrives and almost 900hp of V8 muscle

The blade profiles, curves and cupping were all slightly different. So yet more new props were sent and fitted for further testing. A run from Bembridge to the Royal Motor Yacht Club in Poole to visit friends and MBY’s editor for lunch took a mere 43 minutes during which Thunderstreak clocked 67.8mph. Yet, we were still short of a few hundred rpm – this time on both engines.

Over the winter SMS refined Thunderstreak even more, fitting Lenco racing trim tabs to help level her ride and control lean in crosswinds and installing seawater stainless steel showers over each sterndrive to cool the gearbox oil. Finally, a new stainless steel tie-bar and couplings linked both drives, to keep them pointing in the right direction. Thunderstreak now looked, drove, handled and sounded like a proper raceboat.

Peter Hewitt and SMS also moved the helm and navigator’s stations closer to the centreline and fitted clusters of engine-monitoring dials alongside new Raymarine Axiom screens (the old chartplotter crashed at speeds above 45mph). A clever new throttle-pod on its own stainless pedestal meant the gear and throttle levers now fell perfectly to hand, while new racing bolsters were designed and delivered by skipper Hewitt to the upholsterers in Poole.

The revised helm station with Peter Hewitt’s old racing wheel and new nav gear

Only the old Destroyer-type wheel now looked and felt a little out of place so in an act of extraordinary generosity Peter raided his own trophy cabinet to present me with his old leather and stainless steel steering wheel. It fitted perfectly.

By now the coronavirus pandemic started to make its ugly presence felt. The restoration team had one small tidal window to launch and recover Thunderstreak, allowing my film crew to shoot some footage during sea trials before the lockdown came into effect.

It has been a long and often frustrating journey transforming Tommy Sopwith’s 1963 raceboat back into a useable and faster 2020 contender but the journey has been worth it. The enthusiasm and sheer hard work from the whole restoration team has been a privilege to witness.

The long rebuild proves worth the wait as H400 takes to the Solent once again for her first pre-lockdown sea trials

The sight and sound of this 57-year-old powerboat has thrilled all who’ve encountered her. Laura Levi, who runs the British Powerboat Racing Club quipped recently: “We all know when Thunderstreak is heading out. In fact, the whole of Cowes does! But we have to salute you and your dedication to bring back this historic raceboat.”

Lord Beaverbrook, the son of Sir Max Aitken and close friend of Tommy Sopwith, also made contact in April 2019 to say that as a teenager he had “played” on Thunderstreak back in September 1963, adding: “Of the seven or eight ‘Competition Special’ 31s built by Dick Bertram, Thunderstreak is probably the last still afloat and working today.

‘Her known contemporaries – Surfrider, Rum Runner, Blue Moppie and Lucky Moppie – have long since disappeared or been left to rot in some mud berth. You are now the custodian of the legend.”

I think she’s worth it, don’t you?

Thunderstreak’s History

by Mike James

Tommy Sopwith’s Thunderstreak was originally meant to be a new Bertram 38 from the eponymous Florida yard. However, this new 38 was written off when it was dropped on the dockside while being loaded for shipping to the UK. Dick Bertram agreed to replace it with one of his new Bertram Competition 31s, a limited run of seven or eight specially built race hulls beefed up for offshore racing.

Her sister ships included Surfrider (Charles & Jimmy Gardner), Rum Runner (Harold Abbott/USA), Blue Moppie (Keith Schellenberg) and Lucky Moppie (Dick Bertram/USA) but as far as we know, Thunderstreak is now the only one still in use today.

Thunderstreak raced in the famous Cowes-Torquay-Cowes event on four occasions under Sopwith’s race number 400. In the 1963 race she was leading the 49 other entrants across Lyme Bay when one of her Ford Holman V8s failed. In 1965, Sopwith entered her again with detuned Fords for greater reliability but this time a shaft failed.

The old V-drive shafts, rudders and trim tabs before the conversion to sterndrives began

Keith Schellenberg, who had previously been racing another Bertram Competition 31, Blue Moppie, bought Thunderstreak in time for the 1966 race. Under his race number 995, the Holman-Moody Fords were uprated to 700hp. Again she retired with engine problems.

After a year’s absence from the race circuit, Thunderstreak 995 was acquired by Robert Doxford for the 1969 BP Round Britain marathon and the Cowes-Torquay-Cowes. She was refitted at Whitehalls Shipyard with an ugly cabin and a revised high driving position and re-engined with two 175hp Perkins diesels, but retired from both races. Fable has it that, instead of arriving in Falmouth as planned, Doxford ended up in the Scillies – perhaps due to the number of empty beer cans found beside the compass!

She then faded into obscurity for three decades until discovered, badly deteriorated, in an East London marina as a houseboat. Acquired by Robin Ward in October 2014 after a tip-off by Classic Offshore Powerboat Club’s Mike James, the ‘sheds’ rapidly disappeared under his chainsaw.

Re-powered with period 7-litre Fords from a US powerboat, Thunderstreak returned to her racing state with a replica aerodynamic cabin drawn by publisher and artist Charles Lawrence, competing in the 2015 C-T-C. In the following year’s infamously stormy 2016 race, she was one of only five boats to make it back to the Solent, where she struck an underwater object in sight of the finishing line and was beached on Yarmouth harbour slipway to prevent her from sinking.

First published in the September 2020 issue of Motor Boat & Yachting.