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Case study

Mini-Ranger 2. Recovering lost history

Client: James Fisher Marine Services

June 24, 2021

In its working life, there were more than 2,500 Fairey Barracudas delivered to the Royal Navy’s Fleet Air Arm. That’s more than any other type ordered by the Royal Navy to date.
A three-seat, single engine torpedo bomber, it was launched from aircraft carrier decks during World War II, carrying their lethal load to drop on to targets.

But, despite the numbers that were built, none remain in the UK today, at least not in complete form. However, restoration engineers at the Fleet Air Arm Museum (FAAM) in Yeovilton are looking to change that and a chance find in the English Solent is helping them on their way.

It’s the wreck of a Mk II Fairey Barracuda, discovered in 2018 by James Fisher Marine Services (JFMS) during a UXO survey for a new 204 km long power interconnector between the UK and France as part of the IFA2 (Interconnexion France-Angleterre 2) project.

IFA2 is National Grid’s second electricity subsea interconnector to France and is a joint venture with French System Operator RTE. It will provide an additional 1 GW of capacity, which is enough electricity to power a million homes.

A short flight

The wreck is believed to be one of two Barracuda aircraft. Both were based at Lee-On-Solent, Gosport, and both suffered forced landings in the Solent during WW2, shortly after take-off from HMS Daedalus airfield. While both pilots survived, making it through the remainder of WW2, their planes remained sunk to the seabed.

Recovery of the wreck offered a great opportunity to the Fairey Barracuda restoration effort. But, it also posed a number of challenges, not least the water depth – or rather lack of it. Lying in just 5 m, Robin Fidler, who was then Survey Operations Manager at JFMS, expected to encounter acoustic interference problems tracking his divers due to signals bouncing off the seafloor and sea surface – often referred to as multipath.

Multipath can cause a USBL transceiver at the surface to falsely detect (or completely miss) a genuine reply signal from a transponder, leading to unstable tracking performance. Previous generation USBLs were particularly suspectable to multipath and needed careful setup to overcome the problem – not always successfully. However, the digital signal processing techniques used by all our Ranger 2 USBLs – we call it Wideband 2 – means that multipath is largely a thing of the past, freeing up users to deploy our USBLs virtually anywhere.

“We were really impressed with just how Mini-Ranger 2 operated,” says Fidler. “We thought we were going to have to use a (Fanbeam) laser radar system, tracking a reflective buoy attached to the diver to give us a range and bearing to the diver. We didn’t have to use it once; we could do it all with USBL, no matter what the tide, which made our lives much easier and that’s all we could ask.”

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Mini-Ranger 2 USBL

HPT 3000

WSM 6+


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Aiding the wreck recovery with Mini-Ranger 2

Six divers were used on the three-week project from the Stour jackup barge, with one diver in the water at any one time. The barge itself was fitted with a HPT 3000 transceiver mounted to the side, cabled back to a survey shack where the diving operations were controlled from.

WSM 6+ transponders fitted to each diver’s cylinder enabled the HPT to track every moment of their dive, providing a valuable layer of safety to the operation. Each diver additionally carried one of our Nano transponders in their pocket, to position directly on top of any archaeological finds, so that precise waypoints for each artefact they discovered could be logged (and individually named) in the Mini-Ranger 2 USBL software. This information is then available for offline analysis.

The crash site was heavily silted so it needed to be cleared away so that sections of the aircraft could be lifted out of the water. Artefacts retrieved included one of the pilot’s boots, a boost gauge and the underwing pitot head and mounting bracket – a delicate instrument which would have recorded the aircraft’s airspeed. The fact that this was found intact implies that the Barracuda was almost at stalling speed by the time it reached the water, says Wessex Archaeology’s Senior Project Manager Euan Mc Neill.

FAAM museum curator David Morris, who has been leading the Barracuda rebuild project for several years and visited four other crash sites to retrieve parts, says, “This find is a huge step forward for our project and we can’t wait to get it back to the museum and begin the preservation process.” Ongoing research and archaeological and forensic analysis of the recovered parts will help determine exactly which of the two aircraft the wreck actually is.

Jake Stevens, IFA2 project manager, says, “We are laying interconnector cables in one of the most congested marine and aviation areas in the UK. It’s been vital to have the right technology for our marine surveys.”

Fidler concluded by saying, “The USBL didn’t miss a beat. We were up and running with it quickly meaning that we were able to maximise the 3 week window we had on site.”

For more information about the project and how you can support it, visit Also follow progress regularly at the Fairey Barracuda restoration page on Facebook:

Did you know?

The first prototype Fairey Barracuda was flown in December 1940, not long into World War II, but production models weren’t available for service until 1943. Capable of carrying a single 16inch torpedo, a combination of 250 and 500 lb bombs or anti-submarine depth charges, the Barracuda was a formidable shipping, submarine and land target attack aircraft.

Fairey Barracudas delivered the blows to the German battleship Tirpitz in a two wave attack which, while not sinking it, disabled the Tirpitz and kept her pinned down in Alta Fjord (Northern Norway) making her a sitting target for the heavy RAF bombers. The aircraft also made an impact in the Pacific campaign and was the first all metal, monoplane torpedo bomber ordered by the Royal Navy.



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