A group of car enthusiasts in Australia recently drove a 1978 Toyota Landcruiser seven kilometers on the bottom of the ocean, setting a new world record for the longest underwater drive.
On the morning of July 29th, a bright orange Toyota LandCruiser drove into the northern Australian Sea to the cheers of dozens gathered at Mandorah Beach for a historic attempt. The 1978 “rust bucket” had been bought online by a group of friends for around $5,000 and converted into an insulated electric vehicle able to drive underwater, at depths of several meters. Dubbed the “Mud Crab”, the old short-wheelbase four-wheel drive buggy was meant to cover a distance of 4.3 miles (7km), between Mandorah Beach and Darwin Harbour, and thus set a new world record for the longest distance covered by a car driven underwater.
The team, made up of a number of mechanical engineers and divers, started by converting the old Toyota into an electrical-powered vehicle. Then, to improve the already waterproof nature of the driveline, all components were further insulated with silicone oil. This way, if water should find its way inside the driveline, the oil would leak out and protect the internal components.
Next, the conventional tires were swapped out for two pairs of Maxxis Trepador that could handle the sandy ocean floor. Only they couldn’t be filled with air, as they would provide too much buoyancy, they were filled with water instead, causing their weight to reach 150 kilograms each. Although they were confident the powertrain could handle the pressure, they only tested the car once in salt water before attempting the world’s longest underwater drive.
The group involved in this epic attempt came up with the idea over drinks while discussing a previous attempt dating back to 1983. That had involved a vehicle equipped with a conventional diesel-powered engine equipped with two 60-meter-long pipes for the air intake and exhaust. It was a daring attempt that ended in disaster when the car hit a rock shelf about halfway and could not be restarted.
However, technology has evolved a lot since 1983, and the team behind the Mud Crab project was confident in their chances. There were serious risks involved, such as catching the attention of curious sharke=s or saltwater crocodiles along the way and putting up with the extreme pressure of the ocean floor, but the desire to make history was greater.
The orange LandCruiser entered the Australian Sea at 9 in the morning, and the team expected to reach Darwin Harbour by 5 in the afternoon, but they underestimated the difficulty of driving on the sometimes sandy, sometimes muddy ocean floor. The car got stuck about a dozen times during the 4.3-mile drive and needed assistance to continue its journey. Then there was a gas pipeline that had to be carefully traversed, and, last but not least, there were frequent driver changes.
Because of the massive pressure so deep underwater, the drivers could only spend about 15 minutes at the wheel at a time, and this slowed the mission down even more. However, at around 9 pm, about 12 hours after leaving Mandorah Beach, the 1978 Toyota LandCruiser emerged out of the water of Darwin Harbour to the cheers of hundreds of excited car enthusiasts.
Because of the costs involved, the team will not be appealing for an official Guinness Record, but their 7km underwater drive is considered the longest ever achieved, by quite a large margin.
