Hi guys,
Nick here, I’m a deck cadet and was just wondering about something I found to be interesting.
Given a hypothetical situation where the ship’s steering gear has failed, what alternate methods can be used to steer?
I was thinking maybe using the bow thrusters but how effective would it be in harsh weather conditions and such?
Any thoughts?
Thanks 
Sorry buddy but this probably isn’t the place for this question, and you probably haven’t earned enough respect yet to ask such a question and get a decent answer.
It is kinda like you just learned how to change the oil on your Dad’s truck and then went and asked the research department at GM, “Why don’t you make cars without wheels?”
If your steering gear fails and you are in shallow water you anchor, if you are in deep water you drift. Then you get on the telephone with the company and the Coast Guard and ask them what risks they want you to take with their ship and their territory. No reasonable captain is going to start jury rigging shit like a cowboy in a movie and sailing all over the place anymore. That kinda stuff puts ships on rocks and you in jail.
If you really want to know about things like steering with thrusters, The Shiphandlers Guide, by R.W. Rowe is excellent and is about $200. Shiphandling for the Mariner is much easier to find but is not as good, however you can get it quite cheap, maybe even less than $10. If it isn’t worth it to you to get a good book to add to your library and actually read it, then I don’t know how it was worth it to you to read my thoughts even this far. Besides for all you know I am a deck cadet too.
If you have more than two shafts, differential thrust could work…
[QUOTE=LeakyBrain;136808]Sorry buddy but this probably isn’t the place for this question, and you probably haven’t earned enough respect yet to ask such a question and get a decent answer.
It is kinda like you just learned how to change the oil on your Dad’s truck and then went and asked the research department at GM, “Why don’t you make cars without wheels?”
.[/QUOTE]
Are you an idiot or something? This is a place to learn and share knowledge. Why would you cut down someone’s ambition and/or thirst for knowledge by saying some useless shit like that.
How do you know he doesn’t want to incorporate such a hypthetical scenario into an academic discussion or paper regarding ship’s propulsion/navigation?
According to you maybe he should just write a paper or spend all day thinking about ratios for mixing primer?
I am also someone who is not well-respected enough to chime in on the forum, but in the Navy I remember a few times we did some twisting maneuvers that involved ahead on one shaft and back on another shaft to get into tight areas in port or swing the ship around quickly for whatever reason.
When you make headway, your tunnel thrusters become useless. When you board a ship, look at the maneuvering characteristics posted in the bridge. Usually there’s a chart showing efficiency lost per speed gain on the tunnels, and that is only figured for port conditions. Throw that thought out of the window.
Call a tug. If in heavy Wx you’ll bang the thruster up sucking air Etc, and as previously said will be very ineffective with much headway. More than 2 knots it will be close to useless, and at that speed you will be starting/stoping the ME way too Much.
[QUOTE=LeakyBrain;136808]Sorry buddy but this probably isn’t the place for this question, and you probably haven’t earned enough respect yet to ask such a question and get a decent answer.
It is kinda like you just learned how to change the oil on your Dad’s truck and then went and asked the research department at GM, “Why don’t you make cars without wheels?”.[/QUOTE]
Why don’t you bite the kids head off while you are at it. The fact that he is in school and took the time to ask tells me a lot about him. Respect is a two way street, he can ask whatever he likes.
[QUOTE=LeakyBrain;136808]Sorry buddy but this probably isn’t the place for this question, and you probably haven’t earned enough respect yet to ask such a question and get a decent answer.
It is kinda like you just learned how to change the oil on your Dad’s truck and then went and asked the research department at GM, “Why don’t you make cars without wheels?”
If your steering gear fails and you are in shallow water you anchor, if you are in deep water you drift. Then you get on the telephone with the company and the Coast Guard and ask them what risks they want you to take with their ship and their territory. No reasonable captain is going to start jury rigging shit like a cowboy in a movie and sailing all over the place anymore. That kinda stuff puts ships on rocks and you in jail.
If you really want to know about things like steering with thrusters, The Shiphandlers Guide, by R.W. Rowe is excellent and is about $200. Shiphandling for the Mariner is much easier to find but is not as good, however you can get it quite cheap, maybe even less than $10. If it isn’t worth it to you to get a good book to add to your library and actually read it, then I don’t know how it was worth it to you to read my thoughts even this far. Besides for all you know I am a deck cadet too.[/QUOTE]
Did you learn all of this by reading “How to Avoid Large Ships” by John
Trimmer?
Give the kid a break, he’s here to
learn. If you followed his lead you too may learn a few things.
There are a lot of factors here. Can you take local control? How big is the ship? How many wheels? Are you just trying to keep the bow into the seas? Water depth?
Like everyone has said before, if you are trying to make speed, the thrusters will be useless. However, if you are just trying to keep a heading until help shows up, thrusters could help if the vessel isn’t very large or have a large sail area.
Boats equipped with a swing down thruster or drop down thruster like an osv have been known to limp around on their thruster.
[QUOTE=gulf_engineer;136834]Boats equipped with a swing down thruster or drop down thruster like an osv have been known to limp around on their thruster.[/QUOTE]
I believe this arrangement is sometimes referred to as “take-me-home device”. Another option is a PTO/PTI that can be used to turn the shaft and give the vessel at least some degree of speed and maneuverability in case of main engine failure. Of course, that won’t help if the steering gear fails.
If its just the power units that have failed there might be an emergency hand pump you can line up to the system. If not, disconnect the hydraulic lines to the rams, rig a couple chain falls to the rudder posts and heave too.
I actually just remembered that you can scroll through a copy of The Shiphandlers Guide online here: http://www.scribd.com/doc/6664722/The-Shiphandlers-Guide-Formatted
page 99 includes the phrase "The thruster can be used to steer the ship . . . " and then, of course, gives you the context.
While you have to pay to download it, you can scroll through for free, and again it is an excellent book, and listed as reference many state pilot exams.
One upon a time, I was on a twin screw Tug, light boat enroute to Norfolk, from Savannah, Ga. The lazarette flooded due to bad weather, shorted out the potentiometers, aka limit switches. Caused the steering to fail to answer the helm. The company was going to send a tug to come and get us as we were near Cape Hatteras, I suggested that we put the rudder midships and steer by varying rpms port and starboard and try to make the entrance to Chez bay. The Captain, said he would give a try. We made it without any risk to other vessels or assets. I don’t think we were considered crazy or negligent.
[QUOTE=dmc;137234]One upon a time, I was on a twin screw Tug, light boat enroute to Norfolk, from Savannah, Ga. The lazarette flooded due to bad weather, shorted out the potentiometers, aka limit switches. Caused the steering to fail to answer the helm. The company was going to send a tug to come and get us as we were near Cape Hatteras, I suggested that we put the rudder midships and steer by varying rpms port and starboard and try to make the entrance to Chez bay. The Captain, said he would give a try. We made it without any risk to other vessels or assets. I don’t think we were considered crazy or negligent.[/QUOTE]
A potentiometer is a variable resistor. A limit switch is…a switch. The steering failed because of piss poor maintenance of compartment integrity. Just be thankful you were light boat instead of on the towline.
[QUOTE=anchorman;136818]When you make headway, your tunnel thrusters become useless. When you board a ship, look at the maneuvering characteristics posted in the bridge. Usually there’s a chart showing efficiency lost per speed gain on the tunnels, and that is only figured for port conditions. Throw that thought out of the window.[/QUOTE]
Thrusters often work very well for steering with stern way up to 4 or 5 knots.