Digital electronic displays are a tremendous asset until they give out, then you end up staring at a blank screen having no idea what’s going on. That’s bad enough sitting at a desk, but in a supersonic car blasting across the South African desert, it’s brown trousers time. To avoid this, watch manufacturer Rolex has developed a pair of bespoke analog instruments as backups for the Bloodhound SSC, the jet-powered car being built for an attempt to set a new world land speed record of 1,000 mph (1,609 km/h).

The record attempt, which is scheduled to take place in 2016 on the Hakskeen Pan desert in South Africa, is no weekend drag racer. It’s powered by three engines; a hybrid solid fuel/hydrogen peroxide rocket engine that’s the largest built in Britain in 20 years to give it an initial boost; a 750 bhp F1 engine to run the pump for the rocket; and the jet engine off a Typhoon fighter plane to punch it over the 1,000 mph mark. It goes without saying that an arrangement like this requires some fairly advanced digital displays to make sure the record attempt doesn't end in a damp squib or a fireball. It also means a belt-and-braces approach to the instruments is cheap insurance against disaster.

The problem is that you don’t just stick a Mickey Mouse watch on the dash as a backup. You need something that’s both rugged and accurate enough to keep the driver informed as to speed and time in the event of a systems failure. It has to be specially engineered to withstand a buffeting at one and a half times the speed of sound at zero altitude as well as the temperature variations of the South African desert.

Rolex, already the official timekeeper for the Bloodhound project since 2011, came up with a pair of analog instruments to provide the most critical information during the supersonic run. Set in the left-and right-hand sides of the dash, they consist of an analog chronograph and an analog speedometer.

Their styling leaves no doubt these were built by Rolex, with the green and gold Rolex crown emblem and the inverted triangle at the zero mark on the chronograph dead giveaways. The dials are backlit for high visibility and Rolex says that the instruments are a critical backup in case the digital displays go out during the precision braking operation from 1,000 mph and for timekeeping during the two runs needed to set the record. Though the instruments are connected to the Bloodhound’s power system, they also have internal batteries in the event of a system failure.

Mr Arnaud Boetsch, Communication & Image Director of Rolex SA, says, “Given Rolex’s history in the world of speed, which goes back to an association with Sir Malcolm Campbell during his World Land Speed Record successes in the 1930s, and Bloodhound SSC’s mission to inspire the next generation to embrace science and technology, the partnership with Bloodhound SSC is a natural fit.”

Sources: Bloodhound, Rolex via A Blog to Watch