Warby's Spirit of Australia II

[Renegadenemo]

Converting the Orph to an electric starter/generator, has made a huge difference. So easy to spin the engine up. We have 36volts (3 x 12v batteries) in the boat for the starter and the generator tops them back up while the boat is running.

Would be nice to have such freedom. We'd really struggle to stow an extra battery. It would have to go either right up in the nose where we need extra weight the least or in one of the sponson tops. There is quite literally not a spare millimetre in which we could fit it. And then, of course, we'd have to depart from the historic correctness of that explosive, high-pressure air starting. If we use our other Orph's for something in the future we'll likely convert them.

[Engine 711]

Converting the Orph to an electric starter/generator, has made a huge difference. So easy to spin the engine up. We have 36volts (3 x 12v batteries) in the boat for the starter and the generator tops them back up while the boat is running.

Would be nice to have such freedom. We'd really struggle to stow an extra battery. It would have to go either right up in the nose where we need extra weight the least or in one of the sponson tops. There is quite literally not a spare millimetre in which we could fit it. And then, of course, we'd have to depart from the historic correctness of that explosive, high-pressure air starting. If we use our other Orph's for something in the future we'll likely convert them.

Sorry, I don't see the advantage of Electric Start, here. Perhaps @Blowtorch might explain why its been done, for SoA 2...?

I struggle to think of any Gas Turbine I worked on which had Electric Start.... Err, Industrial Avon (massive motor, in front on the intake, connected to the nose bullet by a scaffold pole size shaft) Generally, Electric Starters got removed and replaced with Air Starters, on the earlier engines - Olympus for instance (Air Start was adopted to give faster starting). Given a free choice, with no limits on size of weight, Hydraulic starting was the fave for Industrial engines - but you need a Lorry size Diesel engine to drive the Hydraulic pack....

[ozjet400]

Simple, ease of operation on water, multiple starts with no waiting , operating in a remote location, plus an experienced team with electric start jet engines,

If the boat was being fired up at an airport every time, air start would be perfect , but it’s not

[Engine 711]

I follow the experience with Electric start argument. Multiple starts would be subject to whatever the limits are on the Starter Motor and/or the Battery packs.

I do not think an Air Starter is likely to kill you, if used correctly. If you REALLY think that, perhaps you should go Electric ASAP.

[Engine 711]

I do not think an Air Starter is likely to kill you, if used correctly. If you REALLY think that, perhaps you should go Electric ASAP.

The starter on it's own is quite a benign thing, really. The bottles of gas required to power it are something else however and are simply inherently more dangerous than the electric system- which was my point.

Actually, for me - the exact reverse is true. As a Diver, bottles of 'gas' (at up to 300 bar), are not scary at all - given usual care & maintenance.

An Air Starter though - running at maybe 100,000 rpm (turbine speed) is potentially scary - but I have actually worked with many GT's using them, often in relatively close proximity. I have also seen what happens when they are run with too little oil, or are run too hard, without cool down - often both - and despite being a right mess internally, nothing came out - all the debris was contained - as designed.

You might conclude I quite like Air Start systems. But - DO check the Oil in the little Motor regularly - not too much, not too little....

[Engine 711]

Exactly what I'm already doing this morning, as it happens.

If the Orph starter is anything like the Tyne unit (which it could be - similiar 'size' of engine), I seem to recall the only certain way to check the oil was the drain the Starter & refill it....? ( one operator broke a lot of Tyne Starters, by not doing this.....)

Do whatever the Orph operating instructions say.....

[Blowtorch]

The starter/generator that we use is a simple fit and forget 28volt aircraft unit. No oil to fill ,easy as your car starter.We use 36volts (3 x 12 volt car batteries ).The unit fits right behind the bullet nose piece on the engine and tops up the batteries within minutes of the engine starting up.
No air bottles to refill, no air compressors needed. Just fill the fuel tank, hit the starter button and go play. Life is good.

[Renegadenemo]

Has to be said, though, air start is much more exciting.

[Engine 711]

@Blowtorch - Neat...!
Just a bit smaller than the Trent 1000 units (which are 250kVa each - 2 per engine).....
But the same basic idea....

@Renegadenemo - Yup....

[Renegadenemo]

If the Orph starter is anything like the Tyne unit (which it could be - similiar 'size' of engine)

Tyne is quite a lot bigger than an Orph' About the same as a Derwent, I'd guess. We have a couple of Derwent starters and with a lot of careful packaging we reckon we'd squeeze one onto the nose of an Orph' in an emergency. Another Lucas-Rotax unit but half as big again.
The Orph' 101 starter (Lucas-Rotax CT1009) is a low pressure unit but K7's Orph' was a 701 that used the HP starter with gas requirements matched to the on board start system. We obtained a HP starter from a museum engine but the 101 gearbox is totally different to the 701 setup so no way would the HP starter (150psi delivery) adapt to our engine. What we did do, however, was look at how it used HP air compared to the LP delivery (35psi) from a start cart as it hit the start turbine. What we discovered was that the HP setup used a set of precision nozzles to direct air onto the turbine vanes (and creates an ear-splitting shriek in the process). That was easy enough to replicate but it's a smaller turbine and a different gear ratio so, though we drastically reduced gas consumption with our hybrid starter, we haven't yet worked out whether it has the capacity to give us one good start from the on board system, which is now restricted to a 2000psi working pressure. It's just another job to be bottomed once we get back from Bute. Would be great to get there with a totally self-contained start system but it wouldn't be safe so that's that.