Tri-cabin Toilet system

[Warren]

One of the Tri-cabins (1984) I am considering has two Mansfield Traveler 911 toilets. The boat has a main holding tank located in a storage area at the base of the stairs to the v birth. Both have what appear to be "holding tanks" at their base.

I'm puzzled as to how this system works.
1) Why would there be a need to have a holding tank at the base of each toilet? This just seems to be another place for leaks to occur. ....why not flush directly to the main holding tank?

2) There appears to be some sort of "Y" valve in the sewage line that controls each toilet....is this standard?....if so how does it work?

Warren

[aaronbocknek]

hi warren. when vessels were required to have holding tanks installed, this was the fastest and easiest way to comply with the regulation. in the initial install, the traveller holding tanks were plumbed to either discharge overboard via seacock/whale pump (manually), or, a 12v macerator system and via deck pump out. the y valve is used to flush aft or forward head, again, via manual pump/12 macerator, or, deck. in later designs, in order to get more capacity, the two head sewage hoses were joined to the larger tank in the storage are forward near the v-berth location. towards the end of the model run, the traveller heads were not used and the vacuflush system incorporated. believe it or not, the traveller head is very popular because it can accomplish two things. 1. onboard holding tank, 9 gallons us, and, tapped into the boats fresh water system via check valve for flushing. it's a style that's been around for several decades and very successful.
hope this helps.
aaron

[Warren]

Aaron,
Thank you for the explanation
Warren