Steering upgrade or not?
12-10-2002, 06:44 AM
#21
Platinum Member
Charter MemberJoin Date: Jan 2001
Location: so. WI
Posts: 1,562
Likes: 0
Received 0 Likes
on
0 Posts
bt-
I've experienced a steering failure in a twin (stock steering, non counter-rotating, no external tie-bar) and it's no fun!
We locked up a starboard engine at WFO (the one with the PS pump on it
) and the boat did a 180 in less than a second on its rubrail. I'm pretty sure that a shallower boat would have rolled over. The wall of spray was so huge, the other boats we were with thought we had. As it was, my hand got caught in the steering wheel as it came around and broke my hand. Without the McCleod bolsters, we would have been ejected.
When a twin with stock steering has a failure, you have a tremendous amount of hydrodynamic drag and force on the failed side, and its more than enough to push the other drive where it wants to. Drag is drag, and it won't matter much which way the prop truns on the drive (are you a little safer with counter-rotation? We turned HARD right, if the boat had a CCW on the port, in theory we would have gone left instead, since that engine was still WFO). Not something I'm curious enough about to go try.
It is also easy to be fooled into thinking that any given external system will keep you perfectly safe in the event of a failure of some type.
The safest systems will be dual-ram, full hydraulic from the helm, with a pump on both engines utilizing a priority valve set-up that shifts pressure to the good pump in case of failure. It's also much harder for the hydrodynamic force of the water over a failed drive to move a dual ram setup violently, since it has to push another ram as well. An external tie-bar is a must, and I've seen some setups have two back there..
IMHO, a good steering system is worth every penny!
Jim
I've experienced a steering failure in a twin (stock steering, non counter-rotating, no external tie-bar) and it's no fun!
We locked up a starboard engine at WFO (the one with the PS pump on it
) and the boat did a 180 in less than a second on its rubrail. I'm pretty sure that a shallower boat would have rolled over. The wall of spray was so huge, the other boats we were with thought we had. As it was, my hand got caught in the steering wheel as it came around and broke my hand. Without the McCleod bolsters, we would have been ejected.When a twin with stock steering has a failure, you have a tremendous amount of hydrodynamic drag and force on the failed side, and its more than enough to push the other drive where it wants to. Drag is drag, and it won't matter much which way the prop truns on the drive (are you a little safer with counter-rotation? We turned HARD right, if the boat had a CCW on the port, in theory we would have gone left instead, since that engine was still WFO). Not something I'm curious enough about to go try.
It is also easy to be fooled into thinking that any given external system will keep you perfectly safe in the event of a failure of some type.
The safest systems will be dual-ram, full hydraulic from the helm, with a pump on both engines utilizing a priority valve set-up that shifts pressure to the good pump in case of failure. It's also much harder for the hydrodynamic force of the water over a failed drive to move a dual ram setup violently, since it has to push another ram as well. An external tie-bar is a must, and I've seen some setups have two back there..
IMHO, a good steering system is worth every penny!
Jim
12-10-2002, 07:38 AM
#22
Powerboatin, I agree with the rest about having external steering. Of course I would prefer you use the FULL hydraulic from the helm station all the way back. Actually, another great benefit from adding the full hydraulic is that you will be able to eliminate the stock steering from off the inside of the engine bay transom and it will give it a much cleaner appearence. Also, by adding the dual rams externally it will actually help add or reinforce some strength to the gimbal housing/ring/pin and keep it from wearing. This is especially true when the drives enter the water after coming off a wave. Have fun and be safe.
Mark/KAAMA
Mark/KAAMA
12-10-2002, 11:45 AM
#23
Registered
Join Date: Nov 2001
Location: Pennsylvania
Posts: 3,385
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for the good feedback jafo. Can't agrue with anything you said. I had two hair raising events this past year with my twin engine, external tie bar, stock steering boat. The first one, I grenaded the SB engine at about 4500rpm. I noticed the tach movement immediately and pulled back. My passenger didn't notice a thing. Boat went straight, but I did have to counter steer some.
The second was more interesting. At WOT, and launching off a huge wave from a 50' or so yacht, the SB engine died in mid air (carb problem from the jolt going in). This one I didn't notice until upon reentry I started turning right very hard. Both interesting events and I guess with external steering I would have felt less feedback?
To add further to a point you made. I think without the excellent bolsters I have, I probably would not have stayed at the helm in the second event. Maybe bolsters are the real safety device to make sure you have.
BT
The second was more interesting. At WOT, and launching off a huge wave from a 50' or so yacht, the SB engine died in mid air (carb problem from the jolt going in). This one I didn't notice until upon reentry I started turning right very hard. Both interesting events and I guess with external steering I would have felt less feedback?
To add further to a point you made. I think without the excellent bolsters I have, I probably would not have stayed at the helm in the second event. Maybe bolsters are the real safety device to make sure you have.
BT
Thread
Thread Starter
Forum
Replies
Last Post
Sydwayz
General Boating Discussion
9
07-25-2004 08:49 PM
