install a weed hatch on an offshore trawler

[balder8]

Hi Captains and Admirals,

I wonder why I do not see weed hatch installed on sea going trawlers like the so incredible narrow boats cruising on Canals in UK.

The system gives oppotunity to clean the propeller when foulded or engaged with debris from inside the lazaret, cockpit or locker.
Of course, there is a lot of litterature about danger of this kind of equipment if seals damaged or badly fitted.

But if you consider more than 6 to 10' above seawater level and serious welding work ( I mean for a steel hull), it would be a great benefit.

When I sailed near Gibraltar on the way to Canary Islands, I have been stucked in nets from morocco fishermen. The boat stopped, it was at night with a serious swell, we spent a coupel of hours to cut this bloody net and fortunately I have not been obliged to swim under the hull,which should have been really too much dangerous.

One engine matters and more if the get home is on the same shaft like on my trawler ( Keypower get-home drive). As well, a small wing engine can also be out of order if the shaft and propeller close from the main shaft and propeller is foulded.
Some large service boats or life boats should have been equiped with weedhatch...

Below a drawing and a picture of a small fishing boat with a weed hatch ( french boatyard Rhea).

 

[Gdavid]

Most ocean capable trawlers would have the center of the prop at least 2' below the water line which would require the well to be pretty deep and potentially further than you can reach with your arm. Interesting idea but limited in use as vessel size increases in my mind.

 

[rslifkin]

Some boats just aren't well suited to it layout wise either. On my boat, for example, installing a hatch to access the props would be impractical, as the fuel tanks are over the props. So you'd either have to find a place to move the tanks, or you'd need to give up half of your fuel capacity. And you'd still have to pull the mattress off the aft bunk to get in there.

 

[balder8]

@Gdavid

well said and true, for example, on my trawler. But I was thinking to an hook with a special knife secured or welded at the end to cut ropes or other debris around the propeller if this happens.

@rslifkin
well said as well, and I agree that, if possible, not an easy task or refit.

 

[Gdavid]

I think the purpose and value would all depend on the intended use and area of operation for the vessel. If you are continually operating in a area so tight that an anchor(s) cannot hold you in a tight enough position, the water is just too foul or cold, or there is just so much vegetation that the running gear is continually fouled it might be more practical. At the same time, it may be more practical to run outboards instead.

I suspect that in most cases, the best defense is being prepared to deploy an anchor on short notice and carrying goggles, fins, a sharp knife, a light and towing insurance/membership cards.

 

[HTurner]

Adding a line cutter on the shaft is much simpler.

 

[OldDan1943]

A towing service is even simpler.

 

[HTurner]

A towing service is even simpler.

Not really... Not preemptive and you'll still have to go down or even worse pay someone to remove the hash of line or net.

 

[FF]

These are common on Brit canal long narrow boats , but they are very shallow draft.


Not a lot of fish / lobster traps off shore , and a clean prop wont help if you hit a Sea Land container.

 

[stubones99]

Based on the drawing, it does not show the bottom of the weed hatch box. On a narrowboat, the weedhatch cover has a plug that fairs the hull down to the hull surface, so there isn't a lot of drag from water being slung up in the weed hatch while underway.

The weed hatch is more like a box, lowered down a sea chest, with a flange on the top to seal off the opening. If you left the bottom open, there would be a lot of drag.

 

[stubones99]

I had a USAF guy want me to put warning signs near the antennas on a tower, to warn helo pilots to stay out of the beam. I told him the keep-out zone is under 10 feet, and if they are that close, the rotor blades would have already hit the tower, so microwave wasn't their biggest worry. It was amazing to shoot a 18 mile microwave link with a 1/4 watt transmitter.

 

[Hippocampus]

Have used a hook knife on a pole when the Spurs haven’t done it. Trying to keep as few holes in a boat seems a good idea. Like seachests/manifolds/standpipes and that’s for small holes. Wouldn’t like a big hole like a weed hatch.

 

[Northern Spy]

I would think that the rudder tiller or quadrant would be in the way of the weed box on many trawlers.