In service with the Royal Navy since 1994, the heavyweight BAE Spearfish torpedo is being upgraded.
Naval Technology describes Spearfish as;
The Spearfish advanced heavy weight torpedo from BAE Systems is effective against submarine and surface threats in oceanic and coastal waters. The 1.85t torpedo is in service with the submarine fleet of the UK Royal Navy. The Spearfish carries Aluminised PBX explosive warhead of 300kg and is directed towards the target by high-capacity guide wire system and passive and active sonar. Its power plant is composed of a gas turbine engine using Otto Fuel as a liquid monopropellant, and Hydroxyl Ammonium Perchlorate (HAP) as oxidant. The propulsion system allows the Spearfish to engage targets within 48km at low speed.
This additional £270 million contract is specifically for the manufacture phase of activity that started several years ago as part of the 2009-2019 £369.5 million Torpedo Support Contract.
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The upgrade will address improvements across a broad range of subsystems so that the torpedo remains effective and useful for use in the Royal Navy submarine fleet
The very definition of “monopropellant” says this is bollocks:
“Its power plant is composed of a gas turbine engine using Otto Fuel as a liquid monopropellant, and Hydroxyl Ammonium Perchlorate (HAP) as oxidant.”
A monopropellant needs no oxidizer. https://en.wikipedia.org/wiki/Monopropellant
“A monopropellant needs no oxidizer.”
Correct.
Otto is a monopropellant by every definition.
In this instance HAP is an additional oxidiser to improve the performance further.
http://www.readcube.com/articles/10.1002%2Fprep.200400055?r3_referer=wol&show_checkout=1
@TD
The storage photograph puts the beasts into perspective, eh? Nice find.
Am I right in thinking Spearfish is very fast, but its engine makes such a racket, it deafens its guidance system? Hopefully this upgrade will put that right. No point having £900 million SSNs without a credible torpedo.
Otto 2 or Otto II fuel is a monopropellant.
The text claimed it was “Otto Fuel”, which would be a very different substance.
https://en.wikipedia.org/wiki/Otto_fuel_II
I get it, they use a monopropellant + oxidizer, but the quote was still incorrect.
@John Hartley:
The speed is adjustable and the torpedo is very fast during the terminal attack phase only. Electric engines such as in DM2A4 are certainly more silent (and likely slower), though. The spearfish’s pump-jet tail is meant to reduce noise emissions.
I must admit, that despite my best efforts, I don’t know a whole lot about Spearfish (Very deliberate I am sure and I could understand the Navy being Cagey about one of its most important assets!)
Don’t suppose anyone here knows generally how spearfish is regarded and maybe what the upgrade is specifically addressing? I am hoping its considerably better value for money than its predecessor and that we aren’t still preferring to go after cruisers with antique trops ;-)
Today’s upgrade statement states “single fuel instead of OTTO/HAP” can anybody say which fuel and any known effect on speed and/or range please?