You stated the issue was with increased use lowering the vacuum.
If you have a clog, you should have a vacuum timer alarm installed ahead of the potential clog point. I have multiple in my go bag for this reason.
Repeated clogs indicate an obstruction, obstructions can be located via borescope and removed. I’ve heard lots of excuses about this old system is all narrowed up etc etc and I’ve never seen one that didn’t clog in one of a couple obstruction points that could have and should have been repaired years ago.
A junior engineer attempting to just vacuum a clog out indicates a lack of gauges, poor training, and an unwillingness to touch shit.
The next time you have your book out or ceiling panel removed, look at the entry point from the vertical pipe from the toilet to the lateral line in the overhead. The entry points are designed to go up over the lateral line then enter from the top. Like an upside down p-trap. Ideally by entering from the top it will prevent the vertical line & toilet from backflooding in case of lose of vacuum. The longer the lateral line, the sharper the upside down ptrap entry points have to be because the lateral line must be slooped when on an even keel. There’s only so much overhead space to work with which causes sharp turns at the ends. Also, the decks above have to be supported by the deck beams. I found the overhead deck beams to be the #1 cause of restrictions points. We can’t cut them out or drill through them. I’ve never seen a sewage vacuum system that didn’t go against its drawings & slooping lateral lines principle because of the necessity of the overhead deck beams. Bigger the ship, the worse it is. Not simple.
Every sewage system put on a ship deviates from ideal. Those points can be identified, build up removed and flush fittings installed.
One of the first things I attack on a shipyard proposal is replace this entire sewage line because I know the deal. They believe the entire line is like that. It’s inevitably short sections. Nobody bothered to look.
There was a chemical contained in a bag similar to a teabag that we dosed all the heads once a week. We carried up to 12 passengers and we had very few problems with the vacuum system.
Back in the good ol’ days we never had problems. Heads were flushed over the side by a heavy push on a valve, and firemain pressure water whooshed it over the side a few feet away. Of course, sailors on a punt in harbour painting the ship’s side knew how to evade the onslaught.
Every system I’ve sailed with since has been worse. My navy even suffered a death of a young cadet from gasses in a sewerage system.
My best sewerage story comes from my good ship STS Leeuwin II. The engineer was very reluctantly convinced of the need to feel his way through the day’s doings in the sewage treatment plant (for some reason known as Mr Hanky). A desperate passenger on a day sail had sadly ignored briefings to spew over the side, and lost his false teeth down the heads. His endless, pitiful, toothless pleadings brought me to reluctant and emotional support. The engineer was less emoted but relented after inducement. We had thus recruited a lifelong supporter.
The Ford has a history of issues with the system. A story from 2020:
I assume there is an issue with the system design or details of how it was installed, but that’s pure speculation just based on the reporting over the years.
Years ago I was the Cheng on a large Navy ship docked at Norfolk Naval Station. It had 400 + females and 500+ males onboard.A day did not go by without sewage problems. It was not a vacuum system, but nonetheless it was problematic. Training was held on what should go into a toilet and what not is allowed. Still clogs and backups occurred. So some of my engineers earned the unwanted title of “Turd Chasers”! Every Friday the Executive Officer would go on the ships CCTV and hold up a plastic bag of articles that were found in the sewage piping “ female products, condums, hair brushes, underwear, combs, silverware, pens” to name a few. Despite training and the XO attempts to embarrass sailors it still happened. After the Navy I have sailed on ferries and several river cruise ships that had vacuum toilets. Same issues, flushing stuff down toilets that doesn’t belong. Except now passengers raise hell when their head is OOC. So we narrow it down to a zone, then to a group of cabins, then down to the cabin that’s the culprit and I can confront them with the fact they are to blame! It’s a shitty job but someone has to do it!
When sailing with a 50% female crew we got the standard female blockages and the answer was simple enough. The engineer showed them where the tools were and which pipes to disconnect and left it up to them knowing that there was only one female bathroom.
They learned very quickly.
I learnt also. Whilst doing captain’s rounds with my big torch after a blockage cleanup, I vaguely spied a piece of trash deep under the pipework and said “What’s this piece of shit?” as (too late) I plucked up an actual piece of shit in my fingers. The women scattered as I tried to hand it off unsuccessfully. Graded that part of ship as a fail with rescrub.
On the research ship I work we have the same problem nearly every cruise, most times like clockwork. The first 2 or 3 days out we have a failure. What we started doing is deliberately taking our time & make a show of it. We take panels down that really could stay up. We want everyone who sleeps in the passenger area to know the sewage plant is down. Let them blog, post & podcast about their inconvenience of not having a toilet & bad smells in the hallway. If we can isolate which rooms caused the problem we professionally let everyone know. That actually works pretty good until the end of the cruise. Then we think people get curious & start thinking “what-if” and start flushing stupid shit down the system to just see what happens.
Also, we stopped putting paper towels in passengers rooms years ago. And at least one time that I know of the Master/Client Rep had to confiscate wet-whipes from 1 room. Stupid bastards should have been beat when they were kids, they had no sense whatsoever.
Wet wipes are hell on vacuum toilet systems. We once shut down the system for 12 hours until the captain and myself met with 100% of the crew to explain that wet wipes weren’t allowed. Basically if it doesn’t come off the toilet paper roll or out of your body it doesn’t go in the toilet. The captain then threatened to expose any wet wipe or hemorrhoid wipe depositor the next time this happened because as he said, for what purpose does your rectum need to be that shiny? No issues again once all crews got the speech.
Our dilemma with wet wipes is we can’t forbid them from being aboard. Just forbid them from being flushed down the toilet. Our incident when the Master/Client Rep had to confiscate them was from a fruity ass Karen who thought it was their civil right to flush them down the toilet. The dipshit Karen couldn’t get it through their thick skull that no one was discriminating against him/her/they, no one period was allowed to flush wet wipes. I would prefer to have an Al-Qaeda or Hamas saboteur onboard compared to a Karen saboteur because we can beat the hell out of the former without getting in trouble. The aircraft carrier Gerald R Ford has over 4500 people on board. If 1/4 of 1%, 11 people, are flushing wet wipes, that ship is screwed.
There is a brass plaque available from our marine store worded “Nothing is to be flushed down this toilet that has not passed your lips or toilet tissue.”
Years ago I was on a car carrier with a one leg vacuum leak. The 3AE, a wise and efficient young man gave an amnesty session during a boat drill asked all hands if their toilets were gurgling or sucking air. As to be expected no one knew anything and the situation repeated time and again every few days and again after hand over handing the entire visible piping system the talk was given again, and again no one said a word.
As an eleventh hour Hail Mary pass the 3AE hooked and air fitting to each half of the system and said this was the fairest and most equitable manner to shall we say “flush out” the culprit by blowing 150 psi back through the system. Port side came to nothing, no problem; Stbd. Side blew through and bingo- the 2nd Mate came to dinner madder than a hornet as he said shit blew all over his overhead! We all had a good laugh over this but the moral of the story is if the toilet has problems pay attention and tell someone it only makes things intolerable for everyone else!!
