Front well drainage - typically how does this work?

[Wombat]

I part own a 1995 ex-Ownerships 58ft semi-trad NB built (I am told) by Liverpool Boats (as was). The front well deck is open to the elements and in common with many NBs at first glance you would think it would act as a huge bucket when it rains and fill up with water, which it never does. I am new to this boat which is the first boat I've ever had any ownership of...

 

Question: Typically, how does rainwater drain out of this area? I am assuming it drains to the stern (to be picked up by the stern bilge pump) along the sides of the cabin somehow using the natural bow-to-stern fall of the baseplate? If so are drainage channels formed at the sides somehow to stop water flowing across the general underfloor area?

 

Q is prompted by the fact that we have water accumulating where it shouldn't under the rear cabin floor. NB is soon to be dry docked for investigations and a full survey which hopefully should reveal all. Presently we have the bed removed and much of the floor decking removed; it's not a pretty sight (rotten battens on corroded cross bracing) and clear therefore that this problem is a long-standing one. Potential plumbing culprits are being identified and fixed but I do just need to fully understand the rainwater factor; particularly how it moves from bow to stern (I understand all about engine bay bilge and stern gland etc)

[Guest]

Wombat, on 27 Jan 2015 - 06:42 AM, said:

I part own a 1995 ex-Ownerships 58ft semi-trad NB built (I am told) by Liverpool Boats (as was). The front well deck is open to the elements and in common with many NBs at first glance you would think it would act as a huge bucket when it rains and fill up with water, which it never does. I am new to this boat which is the first boat I've ever had any ownership of...

 

Question: Typically, how does rainwater drain out of this area? I am assuming it drains to the stern (to be picked up by the stern bilge pump) along the sides of the cabin somehow using the natural bow-to-stern fall of the baseplate? If so are drainage channels formed at the sides somehow to stop water flowing across the general underfloor area?

 

Q is prompted by the fact that we have water accumulating where it shouldn't under the rear cabin floor. NB is soon to be dry docked for investigations and a full survey which hopefully should reveal all. Presently we have the bed removed and much of the floor decking removed; it's not a pretty sight (rotten battens on corroded cross bracing) and clear therefore that this problem is a long-standing one. Potential plumbing culprits are being identified and fixed but I do just need to fully understand the rainwater factor; particularly how it moves from bow to stern (I understand all about engine bay bilge and stern gland etc)

Water from the front well deck should drain from small drains in the hull sides at deck level and at the lowest point which often is immediately adjacent to the front cabin wall. No water from the front well deck should get into the cabin/cabin bilge as it should flow through these and over the side of the hull before it would.

 

Your post suggests your drains are either non existent or blocked.

 

ed. - you can see one on this picture. The lower ones further forward are the gas locker vents and the higher one is the well deck drain. They are replicated on both sides obviously.

 

 

PS Welcome - Just noticed this is your first post.

Edited January 27, 2015 by The Dog House

[Old Son]

My well deck employs two sumps each which house a bilge pump. Not the best method but needed due to the depth of the well deck in relation to the water level outside the boat.

[Wombat]

Hmmmm.... Interesting already and thanks for the very fast response - is this forum always this good?!!?...

 

That's what I was expecting Dog House, but the holes as described must be very small if they are there as my pictures of the boat don't show any, and I don't recall spotting them on NBs generally here on the Macc canal, although admittedly I haven't been looking for them (I will be now!) I suppose from a design point of view it all depends on the intended relationship between water level and well deck level.

[Barry]

ed. - you can see one on this picture. The lower ones further forward are the gas locker vents and the higher one is the well deck drain. They are replicated on both sides obviously.

 

 

 

No link to a picture TDH

[Guest]

Hmmmm.... Interesting already and thanks for the very fast response - is this forum always this good?!!?...

 

That's what I was expecting Dog House, but the holes as described must be very small if they are there as my pictures of the boat don't show any, and I don't recall spotting them on NBs generally here on the Macc canal, although admittedly I haven't been looking for them (I will be now!) I suppose from a design point of view it all depends on the intended relationship between water level and well deck level.

Correct on your last point particularly given post 2 and Old Son's design which is something I have not encountered before.

 

As for how common they are well in my experience they are pretty common with a 'modern' Narrowboat built to a similar design to the one I pictured. Every NB we have ever hired and the one we now own (Shell build Colecraft) had/has them.

 

If your well deck is of the same level it actually should not be too difficult job for someone to be able to fashion some for you, ensuring of course you choose the correct spot to ensure the water does actually drain out.

 

It would be more complicated if your well deck floor is a lot lower as in Old Son's case obviously. They clearly cant be below the water level! and if they are too close to it you may find water washing in as the boat is underway which is not really what you want either even if it drains back when the boat slows or stops, like some gas lockers.

 

No link to a picture TDH

Yes how weird - its gone!.

 

have posted another.

Edited January 27, 2015 by The Dog House

[andyb116]

If it's like some of the share boats I work on that have a lowered well deck, there are 2 small drains in the corners of the well deck next to the front bulkhead, these drain through steel tubes all the way to the engine bay, you should be able to see the tubes coming out of the engine bay bulkhead in the corners above the base plate next to the swim, the water is then takan away by the bilge pump. Possible one of the tubes has corroded through, thus leaking water into the internal bilge. Hope this helps.

[Ray T]

Our boat, a Reeves hull has the same arrangement as post #7. We have a deep cratch, being the full internal depth of the boat. There are deck boards across however.

The drain tubes are at almost floor level in lockers on the LH & RH sides of the hull. The lockers have a 1/2 inch gap at the bottom so any water will drain to the sides and hopefully down the tubes and into the engine bay bilge.

 

Not the most satisfactory of arrangements, I agree. This is why we need a cratch cover.

 

This is a piccy when we first bought the boat, but it gives an idea of the depth:

 

random 067

Edited January 27, 2015 by Ray T

[nicknorman]

I'm guessing that as a general concept, boats with stainless steel water tanks have them under the well deck, which means the well deck floor is raised above the water line allowing for drainage from holes in the side, whereas boats with an integral water tank tend to have it in the bow, allowing the well deck floor to be lower and below the water line, requiring remote or powered drainage.

[BruceinSanity]

A '95 O/S boat will be a Reeves shell with a Milburn fit out, I reckon. The well deck is low, below the waterline, so drains as described by andyb and RayT. The pipes run under the cabin floor to the stern bilge and it seems very likely that one has failed.

[alan_fincher]

I'm guessing that as a general concept, boats with stainless steel water tanks have them under the well deck, which means the well deck floor is raised above the water line allowing for drainage from holes in the side, whereas boats with an integral water tank tend to have it in the bow, allowing the well deck floor to be lower and below the water line, requiring remote or powered drainage.

 

That would be a bad guess, I think.

 

I would say it is more normal for integral tanks to extend under the well deck. That's why there is so often a bolted sealed hatch in the well deck area to give access to the tank for cleaning and painting.

 

I have to admit I'm very surprised how many people are reporting boats less than 20 years old where the well deck is lower than canal level, and which therefore rely on some kind of drain tube running right through the boat to the back.

 

I thought this dodgy approach had largely died out many years previously. Apart from keeping unblocked, assuming a steel construction, how do you protect such drain tubes from corrosion? This sounds exactly like the kind of thing that caused issues in much older boats built by the likes of Harborough Marine or Fernie.

 

When we bought Chalice, (1995 boat) I can't recall seeing a single boat of similar age where the front deck was not self draining. Anything else in a "modern build" sounds bonkers to me.

[Ray T]

Alan our boat is a 1998 Reeves build with a Weltonfield fit out.

 

Like you I am not happy with the drain tube idea but it was a small consideration with the purchase of the boat at the time.

Before we had the boat repainted I pumped some hot used engine oil down these tubes. I suppose another suggestion could be Waxoyl with a 40ft application tube.

[Neil Smith]

If it is a corroded pipe you might be able to push a smaller diameter plastic pipe down it and seal around the edge with marine flex or similar.

 

Neil

[Guest]

I'm guessing that as a general concept, boats with stainless steel water tanks have them under the well deck, which means the well deck floor is raised above the water line allowing for drainage from holes in the side, whereas boats with an integral water tank tend to have it in the bow, allowing the well deck floor to be lower and below the water line, requiring remote or powered drainage.

Our Colecraft shell has an integral water tank with a hatch in the well deck floor to acess it. The well deck is also self draining in the way I described in post #2. So I'm not sure what you described could be considered a 'general concept' TBH given Colecraft's position in the boat construction business. (Though I accept not all their shells may be the same design as ours).

Edited January 27, 2015 by The Dog House

[Neil2]

IIRC Hancock and Lane continued with this practice well after most had ditched the wet bilge system, I assume simply because some owners liked the deep front well which gave almost level access from the cabin. Some of their boats had twin "saddle" type water tanks within the cabin are that served as bench seats. I can't think why a deep front well should be a priority to many people but it clearly was.

 

As others have said, the system relies on the pipes transporting the surface water remaining sound and unblocked, and a reliable automatic bilge pump.

 

But if you had a boat like this you would fit a cratch cover PDQ I reckon.

[nicknorman]

Our Colecraft shell has an integral water tank with a hatch in the well deck floor to acess it. The well deck is also self draining in the way I described in post #2. So I'm not sure what you described could be considered a 'general concept' TBH given Colecraft's position in the boat construction business. (Though I accept not all their shells may be the same design as ours).

Ok well it was just a guess, and clearly a wrong one!

[David Schweizer]

Our boat was built in 1982 and has a deep hull. The front well deck is below the waterline, and we have a 15" deep water tank under that!! there is a large sump at the back of the front well, which is emptied by means of a large bilge pump.

 

One of the first things I did after we bought the boat was to build a deck board and have a cratch cover fitted. Seventeen years on I have only had to pump the sump out twice, and in both instances it was because of very leaky lock walls rather than rain.

 

The advantage is that we have an almost full height front cabin door, and we can stand up inside the well without bashing our heads on the top plank. There is always the potential for a minor flooding disater however, I prefer our present arrangement rather than the situation on modern boats, where you have to stoop almost doubled up to get through 4ft high front cabin door.

Edited January 27, 2015 by David Schweizer

[Alan de Enfield]

Alan our boat is a 1998 Reeves build with a Weltonfield fit out.

 

 

 

Exactly ditto.

 

Deep well deck and piped to the stern - cratch cover stops water being a problem.

[Neil2]

I'm guessing that as a general concept, boats with stainless steel water tanks have them under the well deck, which means the well deck floor is raised above the water line allowing for drainage from holes in the side, whereas boats with an integral water tank tend to have it in the bow, allowing the well deck floor to be lower and below the water line, requiring remote or powered drainage.

I suspect the reason for having the integral tank in the bow, (if in fact this is the more usual practice, I don't know) is it allows a proper hatch with a flanged lid to be fitted. You could do this with a tank under the well deck but a raised lid would be a trip hazard. Having said that I have a tank under the front well with a flush lid and I am going to have it replaced with a raised lid when the boat comes out in the Spring.

Our boat was built in 1982 and has a deep hull. The front well deck is below the waterline, and we have a 15" deep water tank under that!! there is a large sump at the back of the front well, which is emptied by means of a large bilge pump.

 

One of the first things I did after we bought the boat was to build a deck board and have a cratch cover fitted. Seventeen years on I have only had to pump the sump out twice, and in both instances it was because of very leaky lock walls rather than rain.

 

The advantage is that we have an almost full height front cabin door, and we can stand up inside the well without bashing our heads on the top plank. There is always the potential for a minor flooding disater however, I prefer our present arrangement rather than the situation on modern boats, where you have to stoop almost doubled up to get through 4ft high front cabin door.

Ah, this starts to make a bit of sense now. I can see a big advantage if you have a cratch cover being able to stand up in the front well and if you have a non self draining well - you are going to have a cratch cover!

 

I'm actually starting to feel a little envious now.

[David Schweizer]

I suspect the reason for having the integral tank in the bow, (if in fact this is the more usual practice, I don't know) is it allows a proper hatch with a flanged lid to be fitted. You could do this with a tank under the well deck but a raised lid would be a trip hazard. Having said that I have a tank under the front well with a flush lid and I am going to have it replaced with a raised lid when the boat comes out in the Spring.

 

Most boats with a water tank below the front ell deck do not have a raised cover. Some, like ours have a 10mm steel, plate bolted over a large rectangular hole with bolt heads protruding, but as with your boat, most modern boats tend to have a cover level with the deck, secured by countersunk machine screws. We overcome the very minor trip hazzard issue by having a piece of waterproof industrial carpet covering the well deck.

Edited January 27, 2015 by David Schweizer

[alan_fincher]

Chalice doesn't have a deck board or cratch cover, so when boating the well deck is a freely accessible open space that just drains out through a large drain hole in each hull side, just forward of the front of the cabin.

 

I have to say that when we did the tidal Thames in pretty rough conditions, large waves were regularly coming over the front and the gunwales, and the water was pouring back out very rapidly through these drains, to stop the front deck, (and ultimately the cabin) from flooding. I certainly wouldn't have wanted to be dependent on just a bilge pump (or pumps) to shift it away fast enough, so I don't think I would want to take a boat out into those conditions that wasn't designed to self drain, unless a cratch cover were left tightly secured in place throughout the passage!

[Guest]

Chalice doesn't have a deck board or cratch cover, so when boating the well deck is a freely accessible open space that just drains out through a large drain hole in each hull side, just forward of the front of the cabin.I have to say that when we did the tidal Thames in pretty rough conditions, large waves were regularly coming over the front and the gunwales, and the water was pouring back out very rapidly through these drains, to stop the front deck, (and ultimately the cabin) from flooding. I certainly wouldn't have wanted to be dependent on just a bilge pump (or pumps) to shift it away fast enough, so I don't think I would want to take a boat out into those conditions that wasn't designed to self drain, unless a cratch cover were left tightly secured in place throughout the passage!

Similarly when we put our longish boat in a shortish lock with leaky double top gates we get a deluge in the front well deck if I've forgotten to secure the cover.

 

It does as you say drain out pretty sharpish but if it didn't I would make pretty sure I didn't forget!

[pearley]

We had a share in Sundowner from 1999 when it was launched until 2007 when we had Joanie M built. It was a Pat Buckle shell and fitout (I didn't think the Reeves/Millburn boats started until 2000) with a lowered from deck with a large drain hole in the rear centre. This constantly blocked from dirt and leaves and after a couple of years 2 small (10 or 12 mm) holes were added in the corners of the deck. These still blocked and required constant attention to keep them clear. The big problem arose during the winter time when the boat had less use when rain would fill the front well and then overflow the door threshold and fill the dry bilge. As we were often the first in the season to use the boat it became the practice to lift the carpet at the back, examine the bilge and get it pumped out.

 

A cratch cover would have solved the problem but not all the owners would agree. We saw the boat a couple of years ago and it now has a cover.

 

When Joanie M was built we specified a lowered deck but this time with a sump and bilge pump and a front cover. As others have said it enables us to stand in the front without brushing our heads on the cover. We still have a locker about 10 inches deep under the deck.

Edited January 27, 2015 by pearley

[Wombat]

Many thanks to all who have responded; all very helpful. Comments from andyb116 regarding drain tubes connecting the well deck to the engine bay bilge are of particular interest. I'll be attending the boat next week so I'll be taking a close look into this; the well deck floor level is equal to cabin floor level so there has to be an arrangement for drainage as you describe. I also note the useful suggestion made by Neil Smith about using potentially corroded drain tubes as a conduit to feed a new length of plastic pipe along the length of the boat although the practicality of this as a solution will depend on existing pipe diameter and wall thickness of the new pipe; sealing at the end also being a challenge.

 

Great stuff! Very pleased to have joined this forum; have used a few over the years but this one thus far is getting a big thumbs up from me

Edited January 27, 2015 by Wombat

[Guest]

Many thanks to all who have responded; all very helpful. Comments from andyb116 regarding drain tubes connecting the well deck to the engine bay bilge are of particular interest. I'll be attending the boat next week so I'll be taking a close look into this; the well deck floor level is equal to cabin floor level so there has to be an arrangement for drainage as you describe. I also note the useful suggestion made by Neil Smith about using potentially corroded drain tubes as a conduit to feed a new length of plastic pipe along the length of the boat although the practicality of this as a solution will depend on existing pipe diameter and wall thickness of the new pipe; sealing at the end also being a challenge.

 

Great stuff! Very pleased to have joined this forum; have used a few over the years but this one thus far is getting a big thumbs up from me

I think the success of that plan will depend on the extent of the corrosion, because if it's bad all you will end up with is plastic pipe ends emerging into the cabin bilge. Just the very act of pushing it through could be sufficient to perforate already badly corroded metal.

 

If you are removing the floor any way would it not be best to run completely fresh and independent plastic piping to the stern?

 

Just a thought.