Struggling with single ram to dual ram steering choice.

[RickSE]

Man this is not an easy decision. My boat came with a full hydraulic single ram Latham system. The system is great and I've had no problems with the single ram set up. My biggest concern with the system is what will happen if I hit a rock or solid object at high speed. As I see it, worst case, I will tear the drive off the boat and the drive will swing or pivot out away from the transom on the steering ram. My main concern with this is that as the drive swings out it will likely turn or pitch the boat as it slows down, possibly tossing the occupants. My assumption has been if I have dual ram and the same thing happens the drive will stay centered and not pitch the boat.

Would you guys agree?

I've talked with Latham several times these last few weeks. In my conversation with them today they specifically asked me why I think a second ram is necessary; they do not see the need for a second ram on a small single IO boat, even exceeding 80-MPH. I explained my reasoning and he admitted that he did not know what would happen in the scenario I described but credited me for thinking about safety and not cost. He said we could probably refer my questions to Mr. Latham but in the end I think it's really my decision. He also warned me that as far as he knows a lot of the recent smaller Donzi's did not have solid transoms and that I should verify that my transom is solid all the way across. I really don't think this would be a problem on my boat.

So here's what I'm faced with,
Probably at least $3K in parts, 10" ram, custom left hand ram bracket, LM7 helm since my LM4 is too small for dual rams, hoses, hardware and my install time.
More weight on an already heavy boat.
Piece of mind.

Again the single ram works great and I'm only thinking worst case scenarios here.

I do have a friend that tore his drive off at speed on Powell. I'll talk to him and see what he thinks. I believe he had single ram. His drive came all the way off but fortunately the input shaft broke and stayed in the gimbal bearing plugging what would have been a big hole in the boat.

Thanks for reading. I'd appreciate any comments you guys have.

BTW, Latham has a stock number for the single ram and bracket that I believe is on my boat, #KRSD-7321, 10” ram, custom bracket and hardware, $1541 retail.

[RickSE]

Yes, like that although thats a twin set up and it looks as though they were still putting power through the starboard package causing the boat to turn sharp.

In my case I would loose all power and forward velocity would slow quickly.

[Rootsy]

Rick,

here are my feelings on single vs dual ram and why and where you should use each...

for my situation where i have a cable helm... what do you do if the tiller arm breaks or the cable breaks... the drive flops to the side and you most likely end up in a very unwanted situation... rolled, swamped, ejected... injured, dead.. etc...

essentially on a cable helm where you replace the internal steering ram (which hooks to the tiller arm also), with an external ram you gain 2 things. Positive control of the drive from a much different leverage point, you tighten up the "play" that is in the gimble and uncontrollable with the internal tiller arm system and you add a redundant steering control...

If the cable breaks the proportioning valve will stay stationary or move very slightly and you'll either continue on straight or turn slowly until you can get slowed down. if the ram should break or a bracket or bolt externally you still have manual steering to accomplish the same thing albiet you'll need to use some muscle... Since you are essentially loading the cylinder you alleviate the strain on the cable... all it does basically is actuate the proportioning valve...

on a FULL hydraulic system, helm, rams, etc... i feel that dual ram is mandatory for many of the reasons above... if the helm goes poop the cylinders will not move or move very quickly you can slow down. if one ram or bracket breaks or a hose springs a leak you have ample control with a 2nd cylinder to get slowed or stopped. if you have a single ram and something in the system securing the drive (the single ram) fails you again lose complete control and the drive will quickly turn to one side and you'll be in an unwanted and dangerous situation...

on high hp situations where you put a LOT of stress on the steering components it is good to go dual ram IMO... one cylinder is pushing one is pulling and everything is being kept under control... even in the event of a system failure..

now if you hit something and break the transom assembly.. and the drive exits the boat... a single ram is going to pull the drive stright behind it, if it doesn't break the cylinder first... and it'll act like a big ole rudder.. it is hard to say what the boat will act like but i almost guarantee you that since it is pulling that drag off center you;ll steer to that side, abruptly i am not so sure...

with a dual ram , the drive will probably stay with the boat... beat the hell out of the transom but drag straight behind...

all of this is considering that the trim rams have detached also... if they stay intact ti's a whole nother ball of wax. the drive is going to twist about their axis etc... eithr way i wouldn't want to be in that kind of a situation... twin engine setups.. well watch the video...

for me full helm hydraulic is fine and dandy but i don't like the idea of hydraulic lines running the full length o the boat to a helm directly above my legs and feet and in front of me... i'd rather keep it confined to the engine compartment and i really like the whole hydro-mechanical aspect of a cable helm / add-on system... althought you still fight play in the helm..

again this is just my opinion... fwiw... and i'll probably be running single ram add-on on the 18...

feel free to disagree :D

JR

[blackhawk]

Personally I think you are worrying about something that is going to be a messy situation no matter what. Hitting something hard enough at high speed to tear a drive off the boat is a pretty good impact and trying to predict what may or may not happen is impossible.

[MOP]

I was an OMC mech back when they used trhough transom steering cable what you discribed would happen, the drives would break loose at the trunions and be held offset behind the boat. They would swerve a bit but due to the gross lack of speed compared to todays stuff it was more of a fright then anything else. The odds of it happening are extremely slim but it can. There is an option but I don`t think many would care for the look, that is to mount a steering dampener on the port side. That would help to keep the drive straight.

Phil

[RickSE]

The odds of it happening are extremely slim but it can.

I'm still waiting to hear back from a friend who had this happen. He clipped a rock spire on Powell that was a few feet under water. He had a 24' Cheetah with a blown BBC and was at speed when this happened. In his case it tore the drive completely off the transom mount, steering arm(s) was the only thing that kept the drive from sinking to the bottom. The only thing is that I can't remember if he had single or dual ram.

When you hit something on my lake it don't move and stuff breaks.

[RickSE]

Heard back from my friend who had this happen. Here's what he said,

"Rick, I have the single ram. I was only going about 40-45mph when the drive left the boat. No sudden turns during the coast to a stop. The ram did let the drive beat up the back of the boat as it flopped around though. Bent the ram real good too."

[Dr. Dan]

:smash: 2 years ago in the Northern Bay during the Rock the Bay Poker Run, a guy in a smaller Scarab 26 I think hit a submerged Tree while underway...this was right after Hurricane Ivan had dumped massive amounts of rain over a couple of days....

Anyway, it sunk the boat in seconds...everyone was alright amazingly....wow Matty those Videos are enough to make me park the boat for many seasons...my heart is still in my throat.

Doc :spongebob