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Steering pumps

Discussion in 'Technical Discussion' started by Pascal, Nov 18, 2022.

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  1. Pascal

    Pascal Senior Member

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    Jastram steering, currently with an engine driven pump on each 16V2000 M91

    never gave it much thoughts until doing my preflight before going to the yard last month and the pump which had been pulled off the engine being rebuilt started leaking around the shaft. Isolated it, refilled the system and went to the yard.

    It is possible but not established that the fact the pump was off the engine caused the leak. It now has been rebuilt along with the starboard

    this has lead to a what if discussion with the MTU guys. Turns out the pumps are installed directly on the front of the engines, not a PTO on the gear and on the M91s a leak around the pump shaft would cause hydraulic fluid into the engine with possibly catastrophic consequences

    I am having my hydraulic guy look into powering the two pumps with electric motors, possibly one 240vac and one on 24VDC for redundancy. I know the odd of a failure are low but the thought of wrecking a freshly rebuild engine is worrying me

    any thoughts? Am I overthinking this?
  2. Capt Ralph

    Capt Ralph Senior Member

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    I would hope, as most hang on devices, that the hang-on (PTO) devices back seal would leak out a weep hole and not into the engine.
    Gear driven water pumps, fuel pumps and stabilizer hydraulic pumps that I have dealt with are built this way.
    Now, this may not say much dealing with old Detroit and Cummins equipment. But worth a double check.
    My hang-on Tu-Flo air compressor uses engine oil so it does return its excess oil back into the engine.
  3. Pascal

    Pascal Senior Member

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    Nope. On the older M91, a leak would send fluid into the engine unlike a standard PTO
  4. Capt Ralph

    Capt Ralph Senior Member

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    Ouch. I can understand your concern.

    I do like your electric conversion ideas.
    Are there any electric pumps already available instead of a fab'd assembly?

    Oh, I remember a hydraulic pump mounted on the backside of a belt driven alternator.
    Could be a thought here.
    Last edited: Nov 18, 2022
  5. DOCKMASTER

    DOCKMASTER Senior Member

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  6. Pascal

    Pascal Senior Member

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    These steering pumps aren’t that big so it should not be difficult to power them with electric motors

    Attached Files:

  7. Capt J

    Capt J Senior Member

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    I had this exact thing happen. We kept losing steering fluid. I thought it was the coolers and they looked a little crusty so changed them. It ended up being the engine driven steering pump which did in fact lose probably 1.5 quarts into the motor. It did no damage. It was a C18. In all honesty, a quart or so of hydraulic fluid diluted into 20+ gallons of motor oil isn't going to do a **** thing to the motor.
  8. Pascal

    Pascal Senior Member

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    The Jastram steering system reservoir is at least 7 or 8 gallons. I ll have to check the exact capacity but I know it took over a pail to refill it. I forgot the capacity of the 16V2000s but i think it s about 30 gallons so 20/25% dilution is going to wreck havoc on the engine!
  9. Capt J

    Capt J Senior Member

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    In the very unlikely event the power steering pump leaks, you'll know where the fluid is going long before you lose 7 gallons in an engine.
  10. Pascal

    Pascal Senior Member

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    unlikely yes. But if the leak is at the pump shaft, the fluid will get into the engine…
  11. mapism

    mapism Senior Member

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    Well, better into your engines rather than mine, anyway! :confused:

    @Pascal: couldn't you connect the pumps to the g/box PTOs instead? Or are they already used for something else?
    I like the idea of powering them with electrical motors, anyhow.
    Should also allow a better control of rotation speed, btw.
  12. Pascal

    Pascal Senior Member

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    the gearboxes PTO are used for the hydraulic pumps which power the stabs, windlasses and bow thruster. I guess that why they mounted the smaller steering pumps at the front of the engines. Maybe I m just overthinking this…
  13. Capt Ralph

    Capt Ralph Senior Member

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    Can your MTU guys reflect on how many times it has really happened? Do your MTU techs have access to the MTU support cloud that could also keeps these stats?
    Maybe the big MTU support cloud has an option in the works.
    I can see a intermediate adapter that could offer an external weep hole an seal off the engine? Maybe a whole other pump.
    Going to electric motors still sound cool but the rework with new hoses and a location to mount the new assembly ads to the challenge (expense).

    Knot knowing the agreement you have with the owners and da check book, When these issues came up for our managed boats, I would gather all info and let the owners make the final decision.
    The first question asked back by the owners was; What is the factory config and why do you differ from them??
    I'm on your side with these concerns but you have commented twice,, Maybe I m just overthinking this. Maybe we are..
  14. Capt Ralph

    Capt Ralph Senior Member

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    Oh, Like my piggy back idea behind a belt driven alternator, Some Trac stabilizer pumps behind the clutch, offers a piggy back for an extra PTO.
    Or, Can your stabilizer pump offer some fluid pressure to the steering system?
  15. Pascal

    Pascal Senior Member

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    They ve never seen this failure but it is a possible scenario…

    I think we would be able to convert to electric pumps without having to change hoses, probably just building shelves near the front of the engines. The most complex part of the job maybe the wiring at the panels.

    again the reason for posting this is to get a reality check and find out if I m just getting paranoid and overthinking this.

    ironically I just an NTSB accident report about some barges running aground and sinking after the tug lost steering following a generator failure which killed the electric steering pumps :)
  16. Pascal

    Pascal Senior Member

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    I don’t think I would want to put all my eggs in the same basket….

    I don’t know if I mentioned that when turning into the canal to the yard, on one engine, I got a low main hydraulic alarm. By the time we got in the slings the bow thruster was minutes from shutting down. The failure was caused by a Trac stab lock pin failure which dumped gallons of fluid in the bilge…

    I already have the stabs, bow thruster and windlasses on one hydraulic system, I prefer having the steering system independent :)
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  17. Capt Ralph

    Capt Ralph Senior Member

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    I read that also, dual gen-sets and the mechanic (engineer) could not transfer over quick enough.
    The NTSB also blamed poor maintenance on that failed gen-set a couple thousand hours earlier. Go Figure.
    Never been on a 15000HP push Tug. Never knew their steering relied on 3 phase electric pump motors.
    I would question that design but for what I know, it probably is how it is done,, period...

    And you want to go dual voltage electric?

    3
  18. mapism

    mapism Senior Member

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    All considered, maybe you are indeed overthinking it, but considering that those puppies are worth enough money to buy a nice boat, I'd rather overthink than ignore the possibility.

    Also because, when engine dealers (be them MTU, Cat, MAN... whatever), tell you that they never saw a particular failure, but they also recognize it is possible, more often than not it means that they actually DID see it happen, and were instructed by the HQs to never mention it... o_O
  19. Pascal

    Pascal Senior Member

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    My attitude !
  20. MBevins

    MBevins Senior Member

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