Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 29-11-2019, 18:35   #1
Senior Cruiser
 
unbusted67's Avatar

Cruisers Forum Supporter

Join Date: Dec 2006
Location: Islesboro, ME
Boat: Looking for a new boat
Posts: 2,414
Images: 24
Raw water manifold for safety?

Are there any production boats that use a raw water manifold instead of multiple through hulls to distribute raw water throughout the boat? Doesnít this seem like a better option safety wise than drilling multiple hills in ones hull?
__________________

__________________
__________________________________________
Unbusted67 or just Ben
unbusted67 is offline   Reply With Quote
Old 29-11-2019, 19:00   #2
Registered User

Join Date: Oct 2015
Posts: 1,614
Re: Raw water manifold for safety?

You keep asking these good questions, and I have the same answer.

My Amel 53 has three thruhulls below the level waterline. One serves the forward head toilet and anchor wash down. One the engine, genset, water maker, and ac pumps, and one the aft head toilet. All sink drains go to a common sump and are pumped overboard

Other boats of the same size I have seen with 18 (!) underwater thruhulls. Thatís crazy.
__________________

billknny is offline   Reply With Quote
Old 29-11-2019, 21:27   #3
Registered User
 
Red Sky's Avatar

Join Date: Jan 2013
Location: S.F. Bay Area
Boat: Caliber 40 LRC
Posts: 459
Re: Raw water manifold for safety?

The Caliber 47 has one.
Red Sky is offline   Reply With Quote
Old 29-11-2019, 22:22   #4
Registered User
 
DanaTucker's Avatar

Join Date: Nov 2019
Location: Northern Neck Virginia
Boat: Paceship Acadian Yawl 30 ft
Posts: 20
Re: Raw water manifold for safety?

My Paceship has three. AC, head and heat exchanger for the motor. In theory, your question may have something to do with the amount of water flow for each point it is needed. Think of a sprinkler system for your yard. The more sprinkler heads you have, the larger the manifold needs to be to supply them. That is why most of them are broken down into zones. Just a thought.
__________________
Before crowbars were invented, they had to drink at home!

DanaTucker is offline   Reply With Quote
Old 29-11-2019, 22:41   #5
Registered User
 
Dsanduril's Avatar

Join Date: Aug 2011
Location: Petersburg, AK
Boat: Outremer 50S
Posts: 2,221
Re: Raw water manifold for safety?

Pretty much all of the Dashew designs, power and sail. Jedi can give you the specifics about his Sundeer.
Dsanduril is offline   Reply With Quote
Old 30-11-2019, 00:07   #6
Senior Cruiser

Cruisers Forum Supporter

Join Date: May 2013
Location: Oregon to Alaska
Boat: Wheeler Shipyard 83' ex USCG
Posts: 2,564
Re: Raw water manifold for safety?

Ships and big boats have a vertical pipe in the engine room for a common raw water intake. Each water need is tapped into the main water induction pipe with a shut off valve. Some have an additional pipe for water exit.
Lepke is offline   Reply With Quote
Old 30-11-2019, 05:18   #7
Registered User

Join Date: Nov 2019
Posts: 20
Re: Raw water manifold for safety?

Quote:
Originally Posted by unbusted67 View Post
Are there any production boats that use a raw water manifold instead of multiple through hulls to distribute raw water throughout the boat? Doesnít this seem like a better option safety wise than drilling multiple hills in ones hull?


Sure. A Raw water manifold , with discharge thru a single , above waterline thru Hull , is common

Pictured is the bilge intake manifold

You also need a discharge manifold
Attached Thumbnails
Click image for larger version

Name:	731F8CD4-0FF9-4A22-BB87-66728913067B.jpg
Views:	168
Size:	247.2 KB
ID:	204017  
slug is offline   Reply With Quote
Old 30-11-2019, 06:10   #8
Senior Cruiser
 
tkeithlu's Avatar

Cruisers Forum Supporter

Join Date: Feb 2012
Location: Carrabelle, Florida
Boat: Fiberglas shattering 44' steel trawler
Posts: 1,334
Re: Raw water manifold for safety?

That was one of my prime reasons for rejecting common trawlers as not seaworthy. I have two through hulls - water in and sewage out, and the sewage one stays locked down. The intake requires lots of hose snaking around the engine room for the engine, genset, and watermaker.

It appeared to me that most manufacturers simply put a through hull wherever they needed water, even under engines where you'd never get to them in time if one popped.

By reversing the position of the inlet valve handle, I made it so that pulling a wire in the main salon above the engine room closes the raw water intake.

Good for you for seeking fewer through hulls.
__________________
Never let anything mechanical know that you are in a hurry.
tkeithlu is online now   Reply With Quote
Old 30-11-2019, 08:00   #9
Registered User

Join Date: Nov 2019
Posts: 20
Re: Raw water manifold for safety?

Quote:
Originally Posted by tkeithlu View Post
That was one of my prime reasons for rejecting common trawlers as not seaworthy. I have two through hulls - water in and sewage out, and the sewage one stays locked down. The intake requires lots of hose snaking around the engine room for the engine, genset, and watermaker.

It appeared to me that most manufacturers simply put a through hull wherever they needed water, even under engines where you'd never get to them in time if one popped.

By reversing the position of the inlet valve handle, I made it so that pulling a wire in the main salon above the engine room closes the raw water intake.

Good for you for seeking fewer through hulls.

Sea water intakes that operate while in the Harbour such as air con handle a lot of water and are prone to clogging... weeds plastic bags....

Best practice is to keep seawater service to engines and generators separate

Watermakers need clean water .... keep the intake upstream of waste discharge
slug is offline   Reply With Quote
Old 30-11-2019, 11:02   #10
Registered User

Join Date: Dec 2009
Location: Cruising, now in USVIs
Boat: Taswell 43
Posts: 585
Re: Raw water manifold for safety?

Best I've seen was called a "seachest". It was a quite large diameter tube served by a single big seacock, and had multiple access points (ea with a valve around it and vertically. The one I saw was open at the top, so waterlevels, debris, flow rates, etc could easily be handled/watched/seeviced. I always thought a removable top on it would have been better, for safety, but this one was open.
sailcrazy is offline   Reply With Quote
Old 30-11-2019, 11:26   #11
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 21,793
Re: Raw water manifold for safety?

I think a manifold COULD provide for a small addition of safety, but I think most of the time it degrades safety. Why? because often it is hung right off a thru hull fitting and is heavy made of SS or Bronze. A thru hull fitting is very thin at the root of the thread (worst possible place due to sharp stress risers) If you suspend weight off of it that makes it worse.
I once eliminated 3 or 4 thru hulls and made a manifold. By the time I was complete with extra hoses under floor, fittings/Tee, multiple under waterline clamps I felt much less secure,. A good seacock and fitting well maintained is a nearly fail proof device. Just my 2 cents.
A good manifold mounted to the hull would be better. But still requires a lot of extra hose running around to the location of the end device.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 30-11-2019, 12:51   #12
Registered User
 
Dsanduril's Avatar

Join Date: Aug 2011
Location: Petersburg, AK
Boat: Outremer 50S
Posts: 2,221
Re: Raw water manifold for safety?

^^^

Yes, this is the question I have every time this question comes up. What is the risk of failure of the 30 feet of pipe/hose running through the hull vs. the risk of failure of a through-hull connected to the consumer by 3’ of hose?

Would love to see some real statistics.
Dsanduril is offline   Reply With Quote
Old 30-11-2019, 12:56   #13
Registered User
 
AKA-None's Avatar

Join Date: Oct 2013
Location: Lake City MN
Boat: C&C 27 Mk III
Posts: 659
Re: Raw water manifold for safety?

Consider also that a sea chest will typically entail a larger hole in the hull to feed all that stuff.
__________________
Special knowledge can be a terrible disadvantage if it leads you too far along a path that you cannot explain anymore.
Frank Herbert 'Dune'
AKA-None is offline   Reply With Quote
Old 30-11-2019, 13:08   #14
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 21,793
Re: Raw water manifold for safety?

Quote:
Originally Posted by Dsanduril View Post
^^^

Yes, this is the question I have every time this question comes up. What is the risk of failure of the 30 feet of pipe/hose running through the hull vs. the risk of failure of a through-hull connected to the consumer by 3í of hose?

Would love to see some real statistics.
Either well done is OK I suppose. But there is also the problem with fittings fitting hose well. I have been amazed some times that a wire wound stiff hose can be pulled right off a metal fitting even if double clamped. Other times no way can you get it off.
No real standardization in fitting barb sizes.
Or the opposite problem: hose is so tight you have to lube it and put it in hot water to get it on the fitting. Next thing you see is brand new hose is cracking at the fitting!
I replaced all the thick rubber asian (?) hose on the boat in my avatar when I rebuilt it. That hose had no wire but was very thick wall... like 3/8" thick!
A) I gave myself tendonitis just trying to get the old hose off.
B) I realized that hose without wire will clamp a lot better/tighter than wire wound.
C) the original hose was in very good shape and would have been fine.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 30-11-2019, 13:54   #15
Registered User
 
Simi 60's Avatar

Join Date: Jun 2016
Location: Australia
Boat: Milkraft 60 ex trawler
Posts: 2,206
Re: Raw water manifold for safety?

60 ft trawler.
1 single through hull for the primary engine
1 single through hull for the genset and deckwash.
That is all.
__________________

Simi 60 is offline   Reply With Quote
Reply

Tags
raw water, safety, water

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Raw Water Manifold? Kefaa Engines and Propulsion Systems 5 15-04-2016 02:52
Converting From Raw Water to Fresh Water Cooling resilientg Engines and Propulsion Systems 11 19-09-2013 23:10
Raw-water to fresh-water cooling conversion Catamount Engines and Propulsion Systems 31 06-05-2012 08:29
Raw Water Pump vs Fresh Water Pump Cheechako Engines and Propulsion Systems 44 01-02-2012 15:31
'Hagane' Update 03-22-10 Raw Water Manifold rustypirate Construction, Maintenance & Refit 5 23-03-2010 19:40

Advertise Here


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 08:43.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×

ShowCase vBulletin Plugins by Drive Thru Online, Inc.