Modern Auto Pilots

mikeg
8th October 2007, 11:25
The thread about 'Iron Mike' highlighted some of the early and not always successful attempts at building a reliable and accurate autopilot.

Today with the high cost of bunkers poor steering ability will enevitably cost money. Many autopilots are now very complex with a variety of sensor interfaces such as the Gyrocompass, Magnetic or fluxgate Compass, GPS Receiver, Log and sometimes also Sea temperature, GPS receiver, ECDIS for track control and even a anemometer input.

I know its not a nostalgia question but I would be interested to know if, considering all those inputs and complexity, the reliablity and steering accuracy has in real terms really been achieved?

Mike
(Not Iron Mike) (Jester)

G0SLP
8th October 2007, 17:42
It seems that there is too much complexity built into modern machinery.

People are shocked when things fail these days, but as an Engineer I'm always amazed when things work (*))

mikeg
8th October 2007, 18:27
I agree, over complexity just requires a skilled technician to fix it. I wonder if the sea-going techs are kept up to date with the latest technology i.e. manufacturers courses, company paid training etc?

Mike

Moulder
8th October 2007, 20:03
I remember on one of Jebsens small North Sea bulkies - mv Clydenes - we had a Decca Auto-Pilot (can't remember the model). Must have been an inherent design fault allowing too much voltage across the command relay contacts (should have been limited to 24 volts but was far in excess of this).
After a couple of voyages they started "pitting" (build up of carbon deposits due to sparking) - then, you've guessed it - one day in a fjord the starboard relay got stuck - sent a voltage down to the steering gear and away we went, merrily merrily in a starb'd circle!!

I never trusted an auto-pilot for many years after that.

Steve.
(Thumb)

James_C
8th October 2007, 20:34
I remember sailing on one coaster and her autopilot was one of those with the dial imposed on a compass rose (might have been a Decca?). Anyway, unlike many modern AP's which lock onto your current heading when you switch over from manual, you did of course have to physically reset this thing otherwise you'd take off in whatever direction as it tries to resume the previous AP course.
Well, it had to happen that someone would forget at some point and the place was the Tyne! We'd just dropped the Pilot inside the breakwaters (think it was a bit poor outside) and as soon as he stepped off, the Old Man switched her over into automatic, just as we were about to go through the piers (a couple of ship lengths away). She did of course try to resume the earlier course, which happened to be a reciprocal of what we were steering (we'd knocked it off in the same place inbound), and so off she went at full rudder to starboard. Cue absolute pandemonium on the bridge as we tried to reset the steering and the Old Man threw the engine astern.
We got her back and got her through the piers no problem though - luckily!
Aye, the parentage of said Autopilot was certainly questioned that day, and the heart skipped a beat (or two).
Had to have a few beers afterwards to 'steady the nerves'. As you do.. LOL
Happy days on the coast!

Santos
8th October 2007, 21:40
I have to say I sailed with some of the best auto pilots there was, human beings. Some seamen I sailed with were brilliant, with wakes as straight as a ram rod, mind you there were others not so hot, but in the main I found that most seamen were excellent on the wheel, took a pride in their steering and also knew their shipmates would have a say if they were not.

Chris.

gas_chief
9th October 2007, 00:26
Hi,

Talking about autopilots, yes the best one is the human one. But if set correctly the autopilot uses a lot less rudder and relieves us of having a man on the wheel all the time. Thee days we have to do with less manpower and that is something that is out of our hands. Coming back to the autopilot, these things hardly ever need servicing. The only Planned Mainitenence job that comes up regularly was dusting the controls! But the settings on it are the crucial part. I have seen many Masters I have sailed with fiddling with the controls to try and get the ship to steer a straight line in the middle of the Pacific. I have failed to understand why it is so necessary to get the ship to steer a straight line in the middle of the Pacific? In coastal waters where the seas are calmer they steer very well.