Horrendous Ship Collision

[captain58sailin]

I've worked on tugs with direct drive reversible Enterprise engines and they were a thing of engineering beauty and worked wonderfully, if they hadn't, it would have been very scary. It is frightening just to watch that accident unfold, so glad there were no crew on the other vessel.

[El Pinguino]

Originally Posted by nigel1

This to can lead to some monumental disasters.
One or our boats working in Australia was heading back to port for crew change, and the engineers ask the skipper if they could take control of the prop pitch (two props), and they would bring the pitch up to maximum engine load to squeeze out every last bit of speed.......

No such thing as a new stuff up.... quite a few ships over the years have knocked over dock cranes etc when the engine goes ahead instead of astern..... where we used to berth in Tasmania they had two identical incidents .... 50 years apart.

Re the rig boat one you mention.... same same on the North West shelf in the early 80's ... I think it was Eastern Tide... went clean under a platform or rig... removed funnels, mast, top of the wheelhouse... skipper very lucky didn't remove bottom of the wheelhouse....

For the rest... variable pitch props are largely the domain of rigboats and ro ro ferries. That said in 1972 I was on a 100,000dwt ship which , only one in her class to have one, had the biggest vp prop in existence at the time. Not for manoeuvering, but to maintain constant load on the engine.... they have since built bigger ones.

[Sssssailor]

Originally Posted by K_V_B

The ship I was on this summer had a big two stroke engine as well. They kept it at constant RPM, and did everything (including reversing) with an adjustable propeller.

Basically the engines' governor would keep the RPM constant, the captain on the bridge adjusted the pitch.

CPP systems are interesting. I worked on a 210' twin screw running off EMDs. They are less efficient due to boss size, but are pretty rugged and you can jockey quite a bit if you need to. Another issue is creep. You think you're at zero pitch near the dock, but the dopler speed log is showing 0.3 kts. Handy if you anticipate it. Confusing if you don't.


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[El Pinguino]

Originally Posted by Sssssailor

CPP systems are interesting. I worked on a 210' twin screw running off EMDs. They are less efficient due to boss size, but are pretty rugged and you can jockey quite a bit if you need to. Another issue is creep. You think you're at zero pitch near the dock, but the dopler speed log is showing 0.3 kts. Handy if you anticipate it. Confusing if you don't.

Was some years on one with 'creep'. As you say if you were aware of it it was ok.
Then some 'bright young man' - of which we had a few - decided to take the creep out while I was on leave and not tell me.... unfortunately he had taken out the ahead creep and introduced astern creep..........

[GrowleyMonster]

My last ship had CRP and a Becker rudder. Nice. But steered awful while slowing down. Once the hull slowed down it steered nicely again. A couple of pilots gave us some tense moments.

[BoatShowAvenue]

Woa! that's a lot of bad luck for a person on a day! I hope no one got hurt !

[gonesail]

the smaller boat looked like a dock fender

[sestina]

Years ago I worked on a 130ft baltic schooner with a direct drive B&W 2 stroke diesel with a feathering prop.

Parking the thing could get quite sporty as the gear change sequence was:

Slow down thr engine revs to idle, which could take a while; de clutch the prop; wind the pitch adjuster like a maniac; engage clutch; rev the engine up, which would take ages.

Whole sequence could take a couple of minutes. Not fun when the quay wall is approaching rapidly. No girly bowthrusters either.

[IdoraKeeper]

Snow mobile? How do you store it on the boat?

[TeddyDiver]

Originally Posted by IdoraKeeper

Snow mobile? How do you store it on the boat?

Dinghy bay? If you have one and it's big enough. Better have a couple of floats tied becouse thought it's possible to drive with skidoo on water it sucks to stop when it usually sinks:rolleyes

https://m.youtube.com/watch?v=MixO-cVgG_w

[Dockhead]

Originally Posted by TeddyDiver

Dinghy bay? If you have one and it's big enough. Better have a couple of floats tied becouse thought it's possible to drive with skidoo on water it sucks to stop when it usually sinks:rolleyes

Kidding aside, that is an essential technique snowmobiling in the spring -- only way to get across a thawed stream.

Scary, but it works. Provided you keep your speed up.

Scariest of all was jumping off a high bank into a non-frozen river. Being the chicken that I am, I waited for several of my pals to get across successfully before trying it myself. Also works -- the momentum of the spinning track launches you back up into the air when you hit the water -- amazing experience.