Waste holding tank question

Dump it through a gravity hose, KISS
may have to tack if a raggie
plenty of seawater does the job for my gravity assist set up

cant see how it’s all gonna get pumped out as some of it will be in or under the hose ?
That might be ideal, but there’s certainly nowhere on our boat to put a tank above the waterline.
 
Mine is like that having fitted it to a mid 1970's boat.
I am wondering about installing a pump out using a tee piece in the outlet to the seacock and then up to deck level, etc. Another project to add to my list ....
I’m intrigued - what problem are you trying to solve, or what additional functionality?
 
Really? I’d say most tanks (except for inland boats) only ever empty by gravity into the sea from the bottom drain. The percentage who ever use a pump out facility or even ever open the top hatch must be small.
Our (sailing boat) waste tank has a shore pump out and a whale pump out both of which are from the top of the tank.
 
I’m intrigued - what problem are you trying to solve, or what additional functionality?
As @PaulRainbow said to be able to use pump out facilities. If the boat has a 5 people on board the tank will only last just over a day as it was a retro fit to cater for when anchored off a swimming beach. I didn't have room for diverter valves to divert number 1's and 2's so it is all a compromise and possibly even fitting a pump out system may not be possible, hence adding to my project list.
 
Ah, this reminds me of a job for my new boat I have been avoiding thinking about.

The macerator pump stopped working just after I bought the boat, and I'm not sure what might be lurking inside the holding tank !

There is an accessible inspection port on the tank top, so I suppose I'll have to take a look. I will report back soon.
 
As @PaulRainbow said to be able to use pump out facilities. If the boat has a 5 people on board the tank will only last just over a day as it was a retro fit to cater for when anchored off a swimming beach. I didn't have room for diverter valves to divert number 1's and 2's so it is all a compromise and possibly even fitting a pump out system may not be possible, hence adding to my project list.
I’m clearly having a senior moment then - I can absolutely see why diverter valves would help if you want to be able to flush 1s not 2s in to the sea to make the tank last longer so a pity if there isn’t enough room. But I’m still not quite getting how a pump out facility helps in the beach scenario as you could release it all into the sea on the way from the beach back to the harbour with the pump out facility. Don’t mind me - I was just curious.
 
Disagree, all boats I know of use a pump to empty the waste tank overboard. The exit pipe in the tank is located at the bottom, connected to a 2" hose with an anti siphon loop, a pump somewhere along the pipe and a sea cock. A dump system without a pump would not empty at all underway and possibly fill up.
Not on my Hanse it does not. Mine is a stainless steel tank as fitted to the 31 & 34 ft versions of Hanse. The bottom of my black water tank is connected straight to the sea cock at the hull outlet. Open that & the contens drain away. Pipe length is circa 2 ft . At sea I leave it open all the time .

Now you mention it there must be some back flooding when heeled over hard. If there is then it would serve to flush the bottom of the tank & the pipe. That can only be a good thing & would clean out the bottom of the tank as the boat tacked.

The pump out pipe goes in the top via a deck fitting & a 6 inch link. There is a vent alongside. The filling point from the heads is at the side of the tank at the top. There is a loop between the heads & the tank

When in the Dutch canals I have used the pump out facilities & there is usually a dipper pipe that pokes down inside the black water tank. Seems to empty the tank Ok but obviously one cannot see inside.
 
On a slightly different note. I decided to take my blackwater tank home, along with the pipe from heads to tank to remove the build up of calcium. The pipe had to be dumped. The calcium had reached as far as the stainless steel elbow, where the entry bend to the tank was sighted. It needed a long screwdriver & hammer..At one end of the pipe the diameter was just enough to get a pencil through.

I borrowed the wife's cree torch from her car- Yes I did ask- & promptly dropped it inside the tank. That was before I had even started cleaning it.
After much hosing - on the patio whist she was out- I was able to see the torch laying there like a glowing turd from my drunken curry days. ?
Unfortunately she came home before I cleaned the patio, so words were exchanged, as she could not get in the kitchen door, so had to take the shopping round to the front. I dared not mention the "turd".;)

Fortunately a cree torch has a clip so using a bent coat hanger so after 45 mins I managed to hook said torch & lift it. But getting it to rotate to come out of the hole needed some whipping twine looped over the end to turn it. I felt like a vet delivering some young as out it popped, flipped high in the air & fell on the floor- & cracked the b..dy lense. Nobody cracks the lense on a cree torch. They are bullet proof- but I did :(
So internet & a cree torch was on the cards. Plus clean the patio with a hose & deck scrubber. But at least I have a clean black water tank & patio & a new hose to boot. ?
Boating is b..y hard work:rolleyes:
 
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On a slightly different note. I decided to take my blackwater tank home, along with the pipe from heads to tank to remove the build up of calcium. The pipe had to be dumped. The calcium had reached as far as the stainless steel elbow, where the entry bend to the tank was sighted. It needed a long screwdriver & hammer..At one end of the pipe the diameter was just enough to get a pencil through.

I borrowed the wife's cree torch from her car- Yes I did ask- & promptly dropped it inside the tank. That was before I had even started cleaning it.
After much hosing - on the patio whist she was out- I was able to see the torch laying there like a glowing turd from my drunken curry days. ?
Unfortunately she came home before I cleaned the patio, so words were exchanged, as she could not get in the kitchen door, so had to take the shopping round to the front. I dared not mention the "turd".;)

Fortunately a cree torch has a clip so using a bent coat hanger so after 45 mins I managed to hook said torch & lift it. But getting it to rotate to come out of the hole needed some whipping twine looped over the end to turn it. I felt like a vet delivering some young as out it popped, flipped high in the air & fell on the floor- & cracked the b..dy lense. Nobody cracks the lense on a cree torch. They are bullet proof- but I did :(
So internet & a cree torch was on the cards. Plus clean the patio with a hose & deck scrubber. But at least I have a clean black water tank & patio & a new hose to boot. ?
Boating is b..y hard work:rolleyes:
Did you have to go back to the boat to get the deck scrubber.
 
Did you have to go back to the boat to get the deck scrubber.
Oh, come off it. :rolleyes: I have a sail loft over the double garage. In there is a lot of my chandlery gear, ropes etc that I sell. Plus, some spare sailing stuff. Every decent sailor has spare boat hooks, sail battens for sails he does not own & deck scrubbers, along with flat fenders & tins of hardened paint. All the important stuff that is useful - even if never used. I mean- What would I do without the roller gooseneck for a wooden boom, or the walker log with no impeller. ;)
When I go I have told the wife that she can cherish them in my memory . She said something like Hurrmpff & about a skip as she retired to the kitchen
She is not really into sailing :rolleyes:
 
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On a slightly different note. I decided to take my blackwater tank home, along with the pipe from heads to tank to remove the build up of calcium. The pipe had to be dumped. The calcium had reached as far as the stainless steel elbow, where the entry bend to the tank was sighted. It needed a long screwdriver & hammer..At one end of the pipe the diameter was just enough to get a pencil through.

I borrowed the wife's cree torch from her car- Yes I did ask- & promptly dropped it inside the tank. That was before I had even started cleaning it.
After much hosing - on the patio whist she was out- I was able to see the torch laying there like a glowing turd from my drunken curry days. ?
Unfortunately she came home before I cleaned the patio, so words were exchanged, as she could not get in the kitchen door, so had to take the shopping round to the front. I dared not mention the "turd".;)

Fortunately a cree torch has a clip so using a bent coat hanger so after 45 mins I managed to hook said torch & lift it. But getting it to rotate to come out of the hole needed some whipping twine looped over the end to turn it. I felt like a vet delivering some young as out it popped, flipped high in the air & fell on the floor- & cracked the b..dy lense. Nobody cracks the lense on a cree torch. They are bullet proof- but I did :(
So internet & a cree torch was on the cards. Plus clean the patio with a hose & deck scrubber. But at least I have a clean black water tank & patio & a new hose to boot. ?
Boating is b..y hard work:rolleyes:
Thank you so much for sharing that. ?
 
What is the point of holding tanks when we have this kind of behaviour:-

Untreated sewage released into Hampshire's Langstone Harbour for 49 hours
When I asked my boatyard owner, on the edge of the upper Hamble and where effectively saltwater meets fresh (subject to rainfall volumes), why we were not yet forced to all have holding tanks, he informed me having the poo discharged directly overboard was a significant factor in the protection of the salt marsh, with the poo effectively feeding the various bugs and creatures that create it.

He added that during Covid lock down, when our boats were effectively banned from being used, the salt marsh was observed to retreat (although we did have a very clear river !), and this is why use of sea toilets and overboard discharges on our rivers is not banned.

Of course this could all be bollocks, but at least quite an interesting theory.

Not sure what the SUP users view of this theory is of course !
 
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