Bilge Pumps - Page 3 - SailNet Community
Reply
 
LinkBack Thread Tools
post #21 of 24 Old 02-08-2007
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 15 Times in 12 Posts
Rep Power: 14
         
I've seen more boats have problems due to water cooling issues, and don't really see the need to risk it on a boat that is already having some issues. If the engine continues to run, you can run as many large electric bilge pumps as you need...but as soon as the engine fails... you're down to your batteries and whatever manual bilge pumps you have...

It is really a personal choice, but I think that having a small bilge pump for the day-to-day stuff, and one or two large bilge pumps for emergency use, that have a higher float switch than the day-to-day pump does makes far more sense. As long as you have diesel and can keep the motor running, you'll have electricity to keep the pumps going. If you use the raw-water cooling as part of the pumping solution and it gets blocked with crud... then you're down a pump, but also have lost most of your electrical generation capacity, and possibly the ability to move your boat toward safety...since the diesel is also powering the prop...

A small hole in the bottom of a boat, say 3' below the waterline because of a grounding, even if it is only an 2" in diameter will let in 136 GPM... Given that most bilge pumps are rated at GPH, not GPM, the largest 12V bilge pump I've been able to spec out rates at 3000 GPH, or 50GPM, which would require three of them to stay ahead of a small 2" hole. That is an optimistic estimate as well, since the pumps are rated at 0' of head, and in this case, we'd have at least 3' of head, to get the water out of the bilge and up past the waterline. I don't believe a raw water cooling system runs at 50 GPM, given the small diameter of most of the tubing and passages in it.

Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
sailingdog is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #22 of 24 Old 02-08-2007
Thanks Courtney.
 
Join Date: Sep 2006
Location: IL
Posts: 3,954
Thanks: 1
Thanked 1 Time in 1 Post
Rep Power: 11
     
Quote:
Originally Posted by Razman23
Im not going to get into the pump debate already going but I would like to suggest that instead of connecting the bilge pump hose to the emergency hand pump hose, you may look at teeing it into the hose from your cockpit scoopers. I dont see any sense in putting ANOTHER hole (granted its has a seacock) below the waterline of your hull if not needed.
Raz- You have to be really carefull with this aproach as it is possible for water from cockpit to backflow down into the bilge.

hunter Legend 37 Semper Paratus
Formerly - Tartan 34C Yawl
T34C is offline  
Quote Quick Reply Share with Facebook
post #23 of 24 Old 02-08-2007
Larus Marinus
 
Idiens's Avatar
 
Join Date: Jan 2007
Location: Brussels
Posts: 1,756
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
SD - I see the engine pump as additional capability. Clearly, choose your pumping capacity and there is always a little bigger hole below the water line that will overcome it. In such circumatances the pumps are just winning time while one struggles to patch or bung the hole.
Yes, crud can stop any pump, but that applies to the electric ones too, so strum boxes are needed with a mesh that only allows acceptable sized dirt through. Since the raw water pump already has a strainer, adding a strum box to the "emergency inlet" plus a Y-valve is a fairly competitive way of increasing the time before the life raft starts looking attractive.
Idiens is offline  
Quote Quick Reply Share with Facebook
post #24 of 24 Old 02-08-2007
Professional Sun Bather
 
Razman23's Avatar
 
Join Date: Jan 2007
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Quote:
Originally Posted by T34C
Raz- You have to be really carefull with this aproach as it is possible for water from cockpit to backflow down into the bilge.
Ah crap! Youre right.....................nevermind.

Raz

~~~_/)~~~
'Have a great sail day!'
Razman23 is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome