Rowana
Two steps lower than the ships' cat
I always thought the Fleet Air Arm were referred to as "Hairy Fairies"
Nasty collision
- Thread starter Salty John
- Start date
I always thought the Fleet Air Arm were referred to as "Hairy Fairies"
A1Sailor
...
HoratioHB
Well-Known Member
Doh!
Mariner69
Well-Known Member
Wanna borrow my copy of Jackspeak?
Now found its out of date with the new generation. Makes one feel slightly old; but not aged.
Now found its out of date with the new generation. Makes one feel slightly old; but not aged.
Uricanejack
Well-Known Member
Both the types of ship in the video clip would most likely have a single fixed pitch direct drive slow speed diesels.
While it is possible some may have CPP or medium speed or even twin screw they would be quite unusual and be built for specific trade where it was a commercial advantage.
One of the most rarely used pieces of equipment on the bridge of a ship is the telegraph or bridge control for the main engine. There often exit’s a reluctance to use a change in speed for collision avoidance due to reaction from senior officers or Master. Quite simple it draws attention. The Chief engineer does not like it due to stress on his engines. But often more due to Charter requirements for speed and fuel consumption.
So Engine movements are often avoided or left for confined water or emergency situations.
The Singapore, Malacca Straights are one of if not the busiest shipping routes in the world. As such and being relatively confined the ships transiting the area will most often do so on “Standby”
“Standby” is a heightened state of awareness or readiness.
Master or Captain, called but may or may not be on bridge particularly for long standby fatigue is an issue.
A pilot is required if anchoring or berthing. If transiting without stopping perhaps not
Extra look outs, Hand steering, Engines on standby, Both radars on radar Plotting(Nowadays using ARPA) (Engine control room Manned, additional generators on line, additional compressors on line) (Reduced from full sea speed and ready for immediate manoeuvre about 70% full RPM) older ships may change over from heavy fuel to diesel.
While it may seem unlikely a ship in close confines could react in time this is not the case. The ship does not have to stop to change the outcome it just has to slow down enough to alter the outcome. A reduction by half would make a significant difference.
If the OOW Officer of the watch was keeping a good lookout and planning ahead an early small reduction in speed or a small change in course would easily solve the problem.
In a very busy area with a lot going on one or both may have been distracted, overloaded, complacent or afraid to act in case angry skipper shows up and asks WTF
Once the close quarters situation is developing and you are close to a collision it is time for emergency manoeuvre., They have screwed up now its time to do what you can to get out of it.
First thing call Capt. Well actually a good or experienced OOW will act first then call the Capt.
In order to Crash Stop. A Slow speed direct drive diesel.
You have to shut the engine down or stop it.
There is no gear box. There is no shaft brake.
It will not stop water pressure will keep it turning even with fuel shut off.
When stopped the camshaft must be moved to alter firing order for going astern.
The engine fires up with firing odder reversed and the screw goes astern.
In an emergency the fastest way to achieve this is to reduce RPM to dead slow ahead.( this will increase drag)
Start cycling rudder hard over to hard over cycling back just as soon as you see each cycle start to have an effect but don’t turn( Fastest way to reduce speed is hard over and turn)
When speed down below about 10kn or possibly 12 or so if you have a really good engineer on duty
Stop engine. On engine control and then double ring full astern(This lets engineer know its an emergency and he will do what it takes regardless of damage as long as it goes) the engineer will move the cam while engine is still turning ahead, he will then fire the starting air into the cylinders until the air pressure stops the engine turning and starts it going astern. When turning astern he put fuel to it and it will go.
At this point half astern may be more effective at first than full due to cavitations. The engineer will use his judgment on when to put full.
The ship will no longer be steer able she will swing 90deg to starboard but a large bulk carrier in the 100,000t to 120,000t range can do it in about a mile and a bit. Add a bit for contacting engineer.
Under ideal conditions for trails. She probably did it in about a mile.
Finally when its to late for the usual emergency response to avoid an imminent collision.
You do what you can to best aid the other vessel to take action and hope he does.
Some of you noticed or thought the smaller vessel went hard to port. Who knows he may have had this intent. If he went to starboard the his stern would have swung to port and he may have been hit just aft of amidships starboard. Or it may just have been interaction and luck.
That would be the official answer
or you make darn sure your bow and collision bulkhead goes into his side
Then you offer assistance that would be what you never say out loud in court.
Its been well over 30 years since I was on a ship with a slow speed diesel.
Modern bridge control system may well be able to do a crash stop as efficiently as an engineer but I doubt it
Give me the ugly old uncert 3rd Geordie, or Jimmy, ship yard time served down bellow any time unfortunately those guys went the way of the Dodo decades ago. And I went sailing instead.
sailorman
Well-Known Member
A great post, thank you
onesea
Well-Known Member
Not arguing with anything said in your post, it was some one else who brought up CPP, I was just highlighting that is not not as simple as it sounds either...
I hope our posts on this thread compliment each other...
Uricanejack
Well-Known Member
I think they do.
After reading your post it just occured to me some people might be interested in a slightly more detail, how they work.
