Bloodhound diary the sound of speed – bbc news database logo

A british team is developing a car that will be capable of reaching 1,000mph (1,610km/h). Powered by a rocket bolted to a eurofighter-typhoon jet engine, the vehicle aims to show its potential by going progressively faster, year after year. In 2018, bloodhound wants to run above 500mph. In 2019, the goal is to raise the existing world land speed record (763mph; 1,228km/h) to 800mph. And in 2020, the intention is to exceed 1,000mph. The racing will take place on hakskeen pan in northern cape, south africa.

Richard met with the south african government, the british high commission team, a whole list of companies (who all want to help) and a range of national media.Million litres water

At supersonic speeds, I don’t have to worry about the jet intake noise anymore, as I’ll be travelling faster than the sound the jet engine is making.


During our "slow speed" (200mph) tests at cornwall airport newquay last year, we found that the cockpit was not as noisy as we had first thought.

We’ve already got a big box of something called "basotech" (the same sound-absorbing foam that ariane rockets use), ready to fit in the cockpit if required.

If it gets too noisy, then we’ll simply move the crowd line back further (don’t worry if you’re coming to see us, it won’t be too far and you’ll still get a fabulous view!).

We’ve already warned them that they are probably going to need wireless timing equipment, as they are likely to be a kilometre of more back from the track.Million litres

For example, the space shuttle had to use massive water sprays to damp down the acoustic energy at launch. And I do mean "massive’ – they sprayed over one million litres of water on to the launch pad in just over half a minute, to prevent acoustic damage to the payload and crew. That’s a lot of water and a lot of noise.

Bloodhound is not going to be using anything the size of the shuttle main engines, which is just as well, as there’s nowhere on the car to keep a million litres of water.

Between them, the rolls-royce jet engine and the nammo hybrid rocket will make bloodhound SSC the loudest (as well as the fastest) car in history.

That’s comfortably above our bloodhound 500 target for this year of 500+ mph, to give us some worst-case noise figures to look at for this year’s testing.Pain threshold

For the test programme, that makes things simpler, as we can focus on two cases – jet engine at full power (measuring the total noise exposure of the car) and jet engine off (measuring the noise from the airflow only, as the car slows down).

Nick can then use these figures to improve the accuracy of his model (if required), before we fit the rocket and start doing supersonic runs.

On this scale, 20 db(SPL) is 10 times the sound intensity of 0 db, and 40 db(SPL) is 100 times the intensity. Confused? Yes, me too. Let’s stick to some simple examples.

If 0 db(SPL) is the quietest sound you can hear, then the "pain threshold" of sound, where the noise starts to cause you injury, is around 120-130 db(SPL).Pain threshold

The variation is because the pain threshold is slightly subjective: a really loud (130 db(SPL)) rock concert may well be "great music" to a 20-year old and "painful noise" to someone over 40….

With 130 db(SPL) as a "painfully loud" reference (at least for me – I’m over 40), the sound levels around BLOODHOUND may make a bit more sense.

I’ll be wearing a full-face helmet and ultimate ear moulded earplugs (like you see the F1 drivers using), so I’m well protected against this level of noise.

Of more interest is the prediction for noise at the back on the car, where the SPL figure is 150 db. This is really quite loud. Unhelpfully, most of the examples of this kind of noise level are things like military jet engines or heavy artillery gunfire.Million litres

More exciting is the sort of effects that it has on the human body, which are variously quoted as "chest cavity vibrates", "giddiness" and "choking".

If you want to see how we get on, come along and join us for our first high-speed test session this autumn in south africa. We’d love to see you there.

A british team is developing a car that will be capable of reaching 1,000mph (1,610km/h). Powered by a rocket bolted to a eurofighter-typhoon jet engine, the vehicle aims to show its potential by going progressively faster, year after year. In 2018, bloodhound wants to run above 500mph. In 2019, the goal is to raise the existing world land speed record (763mph; 1,228km/h) to 800mph.Pain threshold and in 2020, the intention is to exceed 1,000mph. The racing will take place on hakskeen pan in northern cape, south africa.

Richard met with the south african government, the british high commission team, a whole list of companies (who all want to help) and a range of national media.

At supersonic speeds, I don’t have to worry about the jet intake noise anymore, as I’ll be travelling faster than the sound the jet engine is making.

During our "slow speed" (200mph) tests at cornwall airport newquay last year, we found that the cockpit was not as noisy as we had first thought.

We’ve already got a big box of something called "basotech" (the same sound-absorbing foam that ariane rockets use), ready to fit in the cockpit if required.Pain threshold

If it gets too noisy, then we’ll simply move the crowd line back further (don’t worry if you’re coming to see us, it won’t be too far and you’ll still get a fabulous view!).

We’ve already warned them that they are probably going to need wireless timing equipment, as they are likely to be a kilometre of more back from the track.

For example, the space shuttle had to use massive water sprays to damp down the acoustic energy at launch. And I do mean "massive’ – they sprayed over one million litres of water on to the launch pad in just over half a minute, to prevent acoustic damage to the payload and crew. That’s a lot of water and a lot of noise.Million litres water

Bloodhound is not going to be using anything the size of the shuttle main engines, which is just as well, as there’s nowhere on the car to keep a million litres of water.

Between them, the rolls-royce jet engine and the nammo hybrid rocket will make bloodhound SSC the loudest (as well as the fastest) car in history.

That’s comfortably above our bloodhound 500 target for this year of 500+ mph, to give us some worst-case noise figures to look at for this year’s testing.

For the test programme, that makes things simpler, as we can focus on two cases – jet engine at full power (measuring the total noise exposure of the car) and jet engine off (measuring the noise from the airflow only, as the car slows down).Pain threshold

Nick can then use these figures to improve the accuracy of his model (if required), before we fit the rocket and start doing supersonic runs.

On this scale, 20 db(SPL) is 10 times the sound intensity of 0 db, and 40 db(SPL) is 100 times the intensity. Confused? Yes, me too. Let’s stick to some simple examples.

If 0 db(SPL) is the quietest sound you can hear, then the "pain threshold" of sound, where the noise starts to cause you injury, is around 120-130 db(SPL).

The variation is because the pain threshold is slightly subjective: a really loud (130 db(SPL)) rock concert may well be "great music" to a 20-year old and "painful noise" to someone over 40….Pain threshold

With 130 db(SPL) as a "painfully loud" reference (at least for me – I’m over 40), the sound levels around BLOODHOUND may make a bit more sense.

I’ll be wearing a full-face helmet and ultimate ear moulded earplugs (like you see the F1 drivers using), so I’m well protected against this level of noise.

Of more interest is the prediction for noise at the back on the car, where the SPL figure is 150 db. This is really quite loud. Unhelpfully, most of the examples of this kind of noise level are things like military jet engines or heavy artillery gunfire.

More exciting is the sort of effects that it has on the human body, which are variously quoted as "chest cavity vibrates", "giddiness" and "choking".Pain threshold

If you want to see how we get on, come along and join us for our first high-speed test session this autumn in south africa. We’d love to see you there.

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