Lock Prop While Being Towed ?

[OBXSkipper]

I have a friend who asked about having his twin screw boat towed. Sea Tow will be handling the tow, tow is about 20 miles, boat is 32' so it will most likely take several hours. So do You set the shift lever/prop in reverse while towing ? I never have given it much thought and I really don't know. Thanks

 

[psneeld]

I have a friend who asked about having his twin screw boat towed. Sea Tow will be handling the tow, tow is about 20 miles, boat is 32' so it will most likely take several hours. So do You set the shift lever/prop in reverse while towing ? I never have given it much thought and I really don't know. Thanks

Your friend needs to check the transmission and stuffing box manuals ..... no one can guess what needs to be done.

Maybe with transmission models and stuffing box models we may be able to help.

 

[Unclematt]

I keep Pipe clamp vice grips on the boat and lock the shaft with them. Granted the only time I needed them was when the bolts sheared at my marine gear. I think it is best not to have a spinning shaft.

 

[Comodave]

There ia a recent thread about handling a boat with only one engine that talked about free wheeling a prop vs locking the shaft.

 

[jgwinks]

Some non hydraulic gears can be locked by simply putting it in reverse. On others that may cause damage. That won't work on a hydraulic gear and some models recommend not allowing them to free wheel. Safest option is to go ahead and lock it with a wrench or something. I've used a big vice grips clamped on the shaft so the end of the wrench hits something and stops turning. If you're worried about marring the shaft put a rag or something under the jaws.

 

[OBXSkipper]

He's looked and can't find any manuals, it is a velvet drive. Very cramped in er. I did find this and has very good info on towing overall, especially closing seacock on engines, good read.
https://www.passagemaker.com/technical/best-practices-when-under-tow

 

[SteveK]

The tow will likely be near hull speed, lock the shafts

 

[rslifkin]

With velvet drives, being that they say freewheeling under sail is fine, I generally assume that if they're not getting hot, they're fine to freewheel up to near hull speed for most boats. You can't lock one by putting it in gear though, so if you want to lock a shaft it'll have to be done mechanically.

 

[tiltrider1]

While it’s fine to freewheel a velvet drive, it will tow better if the transmission is left in gear for the tow.

I have never seen a velvet drive that didn’t use standard Morse controls. This makes it very easy to just slide it in gear before the tow.

 

[rslifkin]

While it’s fine to freewheel a velvet drive, it will tow better if the transmission is left in gear for the tow.

I have never seen a velvet drive that didn’t use standard Morse controls. This makes it very easy to just slide it in gear before the tow.

They're hydraulic transmissions, so putting it in gear won't do anything. Once the engine is shut down the pump isn't turning and there's no fluid pressure to engage the clutch packs. So all 3 shifter positions become neutral.

 

[SteveK]

They're hydraulic transmissions, so putting it in gear won't do anything. Once the engine is shut down the pump isn't turning and there's no fluid pressure to engage the clutch packs. So all 3 shifter positions become neutral.

I have confirmed that when freewheeling one engine. Only goes into gear when input drive is turning