Hand starting

[pugwash]

What can you fit to an engine (30hp Lister-Petter diesel in my case) to enable hand starting if the electrics fail completely? The point is raised in the interesting "offshore cruiser" post below. My engine can't be cranked. I read somewhere of a spring arrangement that you fit then crank up with several pulls and let go so it turns the engine. I thought it was a good idea but I don't know if it works. Any other options?

 

[tony_brighton]

I recall a story about some solo global racer who needed to start the engine with no battery power. Apparently he rigged a line from the boom around the fly-wheel and gybed the boat - started first time.

 

[Mirelle]

I've seen one. The spring starter can be fitted in place of the usual starter motor and it uses the same Bendix drive arrangement. It is NOT cheap, being made for starting emergency generators for hospitals, etc.

Since it fits where the electric starter would go, it is not a back up system.

 

[nickbailhache]

I once started a diesel with a line to the main boom which was attached to the topping lift. This was then connected to the spinnaker pole on the other side of the mast and a crew member jumped off the pulpit pulling down the spi boom and lifting the main boom. We were fortunate in already having a suitable notch in the front flywheel. I also needed to flick the decompressor and use starting fluid all at the same time.

There was sufficient crew to do this but it was a bit of a 'one shot' exercise which worked. Whilst my engine was only 5 hp, with sufficient line and coordination I see no reason why it should not work. I surprised myself! This was many years ago.

I was then able to recharge the battery sufficiently to continue the weekend.

 

[Gunfleet]

I can start my 1gm with a device bought from French's. It's a pulley for a rope which fits on the front of the motor. You wind the rope round the pulley, decompress, pull like hell (like an outboard) and drop the decompressor. It works.

 

[halcyon]

Bit like the spring starter fitted to forktrucks that work in explosive sites, also used on road compressors, think Lucas were envolved.

Me I got a starting handle.


Brian

 

[incognito]

Room for a nice little invention here... device which gets loaded with a shotgun cartridge but when fired, gives a fast burn, but not an explosive burn, so as to produce a big kick of torque.

If you think that is a bit way out, research Shootit !!

 

[halcyon]

Sorry, already invented, used for starting aircraft engines years ago, may have been used else were as well.

Spring start desiels were used a lot in the past, it ment that the engine needed no electrics.


Brian

 

[vyv_cox]

Sorry, it was invented years ago. Small-medium engines in stand-alone duties have been started using explosive cartridges for many years. Widely used in military diesel engines.

"Small engines are sometimes started manually by turning the crankshaft with a crank or by pulling a rope wound several times around the flywheel. Methods of starting large engines include the inertia starter, which consists of a flywheel that is rotated by hand or by means of an electric motor until its kinetic energy is sufficient to turn the crankshaft, and the explosive starter, which employs the explosion of a blank cartridge to drive a turbine wheel that is coupled to the engine. The inertia and explosive starters are chiefly used to start airplane engines. "

 

[incognito]

Yes... I knew that, but if you applied a straight explosion to our engines, the strength of the components used on our boat engines would not be able to transfer the energy quickly enough to turn the engine over, so something would break - hence the need for a slow burn.

Correct me if I am wrong, but was not the cartridge aero-engine starter applied to produce a turning of the crankshaft but as a direct injection into the combustion chambers?

 

[incognito]

cc Vyz_Cox

Yes... I knew that, but if you applied a straight explosion to our engines, the strength of the components used on our boat engines would not be able to transfer the energy quickly enough to turn the engine over, so something would break - hence the need for a slow burn.

Correct me if I am wrong, but was not the cartridge aero-engine starter applied to produce a turning of the crankshaft but as a direct injection into the combustion chambers?

 

[halcyon]

Not a expert, but the recoil on a shotgun is not that great, ie leaves your shoulder in place, thus cannot be larger than the fuel burn load on the boats engine.
So it would be a good starting point take an engine and fit a cartridge in the cylinder head, problems are sealing the chamber as the engine is working.
But cannot see why a starting handle, spring/air starter, or even an electric starter motor will not do?


Brian

 

[vyv_cox]

Can't tell you a thing about starting aircraft engines but many old stationary and marine oil engines, pretty much a diesel, were started with a cartridge. I doubt very much that firing a cartridge, which is only the expansion of a load of gas, would break a diesel engine. The military starting method referred to in my previous post uses direct expansion as far as I know.

I also know nothing about the cartridges. Anyone watching a fireworks display can see that there are large variations in the explosion rate. Presumably the sort used for starting engines is different from a 12-bore?

 

[pvb]

Why??

Your electrics must be a bit dodgy if you're worrying about a complete failure. There used to be a spring starter on the market, but as Andrew pointed out, it was a substitute for the starter motor, so it wasn't a 5 minute job to get it ready for use!

As long as your engine starting battery is isolated from other circuits, you should always have enough power to crank your engine.

Now, next question, what if the starter motor fails? How many yachts carry a spare? Or indeed, what if the engine blows up? Not many spare engines on yachts.

 

[pugwash]

Re: Why??

My question was posed because somebody in another thread said the ability to hand-start was essential and I wondered if I'd missed something. Of course you're right that good eletrics are best -- certainly better than shotgun cartridges and having the missus bounce on the spinnaker pole. But what a great lot of innovative ideas emerged. Goes to show that if you get stuck on a desert island you'd want to have a few Scuttlebutters looking after you.

 

[Guest]

Re: Why??

I don't understand the logic. What if you hit a rock and your boat sinks? You wouldn't be able to use the engine then either. But I don't see why that means you shouldn't carry spares for the engine. Or an alternative way of starting it.

My starter battery died inconveniently once. Was inconvenient because it did so as I was approaching Dover at night after a difficult passage, just as the domestic battery was also running out of juice. Result: no engine, faded nav lights, not enough power to call on the vhf. I am a great believer in sailing boats being sailing boats and not needing engines to get home, but being in Dover Straits with no lights no engine and no vhf is not funny.

Since then I've found the starting handle for the engine (Yanmar) and will set aside some time to practise trying to start it (there was a useful thread on this not long ago). That's just normal seamanlike precaution. It should cover me for the starter motor failing as you describe. It won't help if the engine blows up, or if I hit a rock, but so what?

 

[pvb]

It\'s great exercise!

I had a boat with a starting handle once. Think it was a Westerly with a 25hp Volvo. One memorable day, I decided to try the hand-start procedure. Moved the decompression levers; engaged the handle; turned it as fast as my energy allowed; dropped one decompression lever; engine stopped dead. Repeated procedure several times, with same depressing result. Vowed always to ensure that my starting battery's charge is preserved. Since then, I haven't had a boat where it's possible to use a starting handle - but I haven't needed one either.

 

[Guest]

Re: It\'s great exercise!

Yes, I had gathered that that is a problem. Mine's a Yanmar 2GM20. There was an interesting thread about starting handles not long ago that had a number of useful suggestions I want to try out.

Apart from a battery that simply dies with old age, problems can arise if the battery is not charging for any reason (in my case the voltage meter had been incorrectly wired so that it showed the engine battery to be fully charged when it was not at all). Or, for example, if someone switches the batteries to "both" for any reason (eg. when charging in absence of splitting diode) and then forgets to switch back to the domestics battery. There are no doubt all sorts of other scenarios where you may have an unusable battery. If it's simply impossible to hand start, then there's nothing to be done about it of course... except start gybing, hanging off spinnaker poles etc.

 

[Guest]

One of the problems associated with hand starting engines is that the front end of the crankshaft is often deep down in the bilge. I had a 30 hp Lister some years ago to which had been fitted a "raised hand start" i.e. an inverted V bracket fitted to the top of engine through the apex of which ran a short axle with starting handle attached. This was connected by a chain to a wheel similar to a bike's drive wheel on the end of the crankshaft.. Using decompression levers (all connected to each other) made starting easy. Good job too, as it didn't have a self starter!

 

[halcyon]

Nearly as bad as the Saab.
Starting handle drives lay shaft with chain spigot, this drives another lay shaft with another spigot, this drives a chain attached to a spigot and pawl on the main crankshaft.


Brian