who knows what might happen!?!
Nothing good.
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How common are pneumatic engine controls running up to the bridge these days? May I ask what types of vessels your company works on?
I’m asking because the bulker “Saint George”, that rammed the lock gate in Holtenau in 2015, seems to have pneumatic engine controls in the engine control room, but electrical ones to the bridge. Similarly, the Offshore supplier “Red Alliance” that rammed the Brunsbüttel lock the same year has electronic steering controls on the bridge.
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“It’s not possible”
“No, it’s necessary”
Americans. Yay.
I enjoyed that scene right up until the last bit where he fires main engines and inexplicably doesn’t spin around the center of rotation of the combined mass of orbiter and shuttle.
Man, I picked a bad day to park next to the wall…
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Thanks for sending those. I enjoy reading such reports. I work on big blue containerships and bulk carriers almost exclusively. I have no experience on the very newest of the ships, so my knowledge of equipment is not comprehensive.
The engine control system in the ECR of the Saint George is similar to what I am used to, although that ship is much smaller than the ones I work on. Our system allows either direct pneumatic control from the bridge, or ECR control mode, which is normal at sea, so that the engineers can fine tune the settings from their end. We switch to bridge control before entering port. The Red7 Alliance is a completely different sort of system.
Here is the Telegraph typical of what I see:
When you move it, there is a satisfying click, followed by a hiss of air, then the white needle follows the handle, which indicates that the engine room has received the command. If you look in the image, the white needle is all the way forward, which indicates Engine Room Control of the engine.
The steering system is Electric on the bridge, and hydraulic in the steering room.
Anyway, those systems are typical of what you would see on most large ships, although the newest ones likely have updated systems. I will ask a friend if the new ones still use air control.
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It seems like a better way to implement a pneumatic control system would be like the braking system on North American railways – in which the system is pressurized in order to release the brakes, and a sudden depressurization of the system causes a full application of all the brakes.
The engine control doesn’t have a secondary signaling function that just rings bells on a corresponding dial in the engine room, letting them know what speed to make? Or is that as outdated as speaking tubes?
Seems like some of those old technologies are not improved by complexification.
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That assumes that stopping is always the safest thing. Much of the ability to steer a large ship comes from the propeller moving water across the rudder. There is a lot of momentum behind a ship underway. It is not going to actually come to a stop for a long time. So you are still zooming along, and quickly losing the ability to control your direction.
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When the engine is in “engine room control”, the telegraph serves as a signaling device, just like a century ago.
An official announcement by the shipping company tells that they had a power plant failure that locked out the steering.
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There is no stopping in the red zone.
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That assumes that stopping is always the safest thing.
Yes this was also true of the Apollo LM. It had two control systems. The PGNS handled approach and landing. The AGS handled abort and return to orbit. Its a bit like a parking brake on a car or bypass radar processing in air traffic control. There is exactly one emergency system. Its well validated and tested regularly in training.
In your earlier reply you mentioned patterns of eroding standards and obviously its a problem all over the place. Two shuttle disasters were blamed on it.
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That makes sense. I suppose more modern ships rely on redundant control systems – maybe fly-by-wire (what’s the nautical version of fly-by-wire?) with backup power
.[quote=“Abraham_Limpo, post:31, topic:99618, full:true”]
An official announcement by the shipping company tells that they had a power plant failure that locked out the steering.
[/quote]
This begs the question – something so important as steering a huge $100 million freighter with a billion’s worth of cargo oughta to have a backup power system so that its control surfaces (and engine controls) will remain active. E.g. most jetliners will have multiple redundant hydraulic systems which reduces the chance of complete failure to a very small value (admitting of course that such failures have much more dramatic results).
The video is of a ferry. But the safety requirements for passenger vessels are fairly strict.
but, every modern ship I have ever worked on has multiple redundancies in the steering system, As follows:
Two entirely separate hydraulic systems, and two hydraulic pumps. Each pump can be used with either system, and these are switched on the bridge. If the system in use fails, it switches automatically to the other system.
The steering can be done in multiple modes. Autopilot, hand steering by wheel, or control of the rudder by a lever on the steering stand, called non-follow-up mode. NFU mode is a paddle that has three positions. More left, more right, and stop. It goes directly to the steering ram solenoids, bypassing everything else. There is a switch on the steering stand to go between the modes.
So, if there is a steering failure, or any other problem on the bridge, the first command is to go to hand steering, if not already there. (Hand steering is about setting the rudder at a particular angle left or right. If you turn the wheel, a rudder command indicator display moves with the wheel. If you spin the wheel to set it at 15 degrees right, The command indicator moves right away, then the rudder starts to move to match 15 degrees right. There is a rudder indicator that lets you see the actual position of the rudder.)
If you switch to hand, and the rudder is not responding properly, you switch systems. If it still does not work, you switch pumps. These switches only take a second or so. If it is still not working, you go to NFU, which lets you control the steering ram directly. If that does not work, you call the engine room. There are multiple power sources for the steering, and they should switch automatically upon failure, but they can switch those manually from the Engine Control Room. They can also send someone to the steering room pretty quickly. If there is no way to control the steering from the bridge, someone in the engine room has the ability to directly switch between all the above systems, and can control the rudder from there, getting orders from the bridge by one of the phone systems installed there, including a sound powered system that does not require power.
If all of the hydraulic pumps and power fail, the guy in the steering gear room can move the rudder by a hand wheel down there. But that is super slow, many turns per degree of rudder change. That is a last resort, and designed primarily to position the rudder manually in drydock.
the power comes from one of usually four or five generators in the engine room, or the emergency generator that is located in a different space, in case of ER fire. When a generator fails, the non emergency lights go out for a second, then everything switches to another source, the lights come back on, and a bunch of alarms start buzzing. the emergency systems and lights are marked with an “E”, and they stay on even when non critical systems are powered down to lower consumption in an emergency.
Ok, we also test all this stuff before getting underway, and before entering coastal waters. That includes a person in the steering room watching the systems switch over, looking for leaks, and checking that the angles indicated on the bridge match the physical rudder angles. We test that each system will automatically switch over if the other fails, and that the alarms all work. During weekly boat drills at sea, we also do drills by introducing various steering failures, and testing the response of the junior officers and helmsman. It is normal to have the best helmsman on the ship take over steering as his duty in an emergency. There are checklists used for all these tests and drills. they are kept as legal documents, and those tests are noted in the bridge and engine logs. Importantly, these documents are signed by the person conducting the test.
But if you don’t have a culture of actually doing all these things, you will not be able to do them efficiently in an emergency. I would put it at 95% that the problems experienced by the ferry could have been dealt with in a way that avoided a collision. I look forward to reading the final report.
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This is all very interesting stuff. Thanks for writing it.
Probably overkill. but there are three or four things that I know a lot about, and this is one of them. That is the strength of diverse communities like this. Between us, we know almost everything. throw out a question, and someone here probably has an answer.
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