Strange weighty thingos

sancho · 01 Feb 2018, 8:17 pm

Hey guys, I'm relatively new to draining and I came across something interesting in a alcove whilst walking through a drain. It was a sized Metal cylindrical weight on a cable connected to a plastic thingo. I'm wondering if anyone knows what purpose it serves? I'm theorising it's for sewerage relief valve but the lack of smell makes me doubt this.
Anyway, thanks dudes

If posting this photo is no Bueno please remove it and scold me I'm sorry.

This is an example of what I'm talking about, I took this photo of one of the dirtier alcoves the other one or two I saw, the other ones were really clean.

Panic! · 02 Feb 2018, 8:25 pm

I've never seen one of those before. But I suspect you're right about it being some sort of sewer relif valve. There appears to be a cylinder above it, and a trap door in the far wall. It would be great if you could stick your camera down there and get a shot looking upwards and further in.
I suspect the weight normally holds an overflow door closed and the cylinder is a float that opens the door. Or it could be a flood gauge. The cylinder flips a switch that somewhere indicates the drain is flooding.
All speculation of course. Which drain is it in? Or Which suburb is the drain in? Please don't advise the exact location.

iso · 05 Feb 2018, 3:52 pm

Panic! wrote: ↑
02 Feb 2018, 8:25 pm
I've never seen one of those before. But I suspect you're right about it being some sort of sewer relif valve. There appears to be a cylinder above it, and a trap door in the far wall. It would be great if you could stick your camera down there and get a shot looking upwards and further in.
I suspect the weight normally holds an overflow door closed and the cylinder is a float that opens the door. Or it could be a flood gauge. The cylinder flips a switch that somewhere indicates the drain is flooding.
All speculation of course. Which drain is it in? Or Which suburb is the drain in? Please don't advise the exact location.

Correct, it's a float for the sewer flap. There are quite a few of these around but this is quite an old one.

As for lack of smell, pop the hatch and catch a whiff

There's the chance it hasn't operated in a very long time, so no guarantee you'll get any stench...

The one at the outfall of Dwellers' Tomb is probably the most active I've encountered... yuck.

Ferret · 05 Feb 2018, 8:09 pm

iso wrote: ↑
05 Feb 2018, 3:52 pm
The one at the outfall of Dwellers' Tomb is probably the most active I've encountered... yuck.

Lol reminds me of the railway entrance to burfords....super crouchy so your head is a meter from the smelly floor covered in s*** and toilet paper making it slippery....and BATS an army of bats pelting into you haha

Panic! · 05 Feb 2018, 8:34 pm

iso wrote: ↑
05 Feb 2018, 3:52 pm
The one at the outfall of Dwellers' Tomb is probably the most active I've encountered... yuck.

LOL. Yeah, I remember that ones. I also remember hunting along there for drains with Id back in the day and popping manholes only to find they were sewers. Yuck.
Oh for the glory days of my youth as a drain explorer.

sancho · 08 Feb 2018, 9:05 pm

Panic! wrote: ↑
02 Feb 2018, 8:25 pm
I've never seen one of those before. But I suspect you're right about it being some sort of sewer relif valve. There appears to be a cylinder above it, and a trap door in the far wall. It would be great if you could stick your camera down there and get a shot looking upwards and further in.
I suspect the weight normally holds an overflow door closed and the cylinder is a float that opens the door. Or it could be a flood gauge. The cylinder flips a switch that somewhere indicates the drain is flooding.
All speculation of course. Which drain is it in? Or Which suburb is the drain in? Please don't advise the exact location.

Yup from memory there was a disk in the roof of the alcove which connected to it all and looked like it would move if i lifted the weight, very quickly decided I didn't want to be involved with that at all.

Drain is Pillars in the northern suburbs (Melbourne). From memory a fair way up the drain. A flood gauge is an interesting thought, didn't seem to connect to any wires though so unless its all self contained and retrieved manually later but I'm not sure.

sancho · 08 Feb 2018, 9:14 pm

iso wrote: ↑
05 Feb 2018, 3:52 pm

Panic! wrote: ↑
02 Feb 2018, 8:25 pm
I've never seen one of those before. But I suspect you're right about it being some sort of sewer relif valve. There appears to be a cylinder above it, and a trap door in the far wall. It would be great if you could stick your camera down there and get a shot looking upwards and further in.
I suspect the weight normally holds an overflow door closed and the cylinder is a float that opens the door. Or it could be a flood gauge. The cylinder flips a switch that somewhere indicates the drain is flooding.
All speculation of course. Which drain is it in? Or Which suburb is the drain in? Please don't advise the exact location.
Correct, it's a float for the sewer flap. There are quite a few of these around but this is quite an old one.

As for lack of smell, pop the hatch and catch a whiff

There's the chance it hasn't operated in a very long time, so no guarantee you'll get any stench...

The one at the outfall of Dwellers' Tomb is probably the most active I've encountered... yuck.

I didn't poke my head in this one, but I did on one of the cleaner ones further up and you could get a good look of the system in there, that's when i got a bit of smell but it just didn't seem strong enough to be crap but hey I suppose that's a good thing.

That said though my neighbour recently opened the pits out the front of my house.
Long story but he had a blockage and wanted to put the hose in my stormwater pit in the backyard to see how mine was flowing as we share a single stormwater drain (apparently anyway, due to shitty subdivision).
So he opens both lids in search of the stormwater, and the first one he opened was sewer, again no smell? but he wasn't sure it was sewer, I had to point out the "-S" on the lid (MMBW-S) meant it was sewer. So he opens the one next to it, proceeds to leave the sewer lid off in the middle of the footpath, with no bollards or gates and a 2 meter drop straight into a sewer pit. I stuck around to make it as safe I could but wow some people are dumb. He didn't even need the sewer open, just left it open till he was done looking in the stormwater pit.

iso · 09 Feb 2018, 1:27 pm

iso wrote: ↑
05 Feb 2018, 3:52 pm

Panic! wrote: ↑
02 Feb 2018, 8:25 pm
I've never seen one of those before. But I suspect you're right about it being some sort of sewer relif valve. There appears to be a cylinder above it, and a trap door in the far wall. It would be great if you could stick your camera down there and get a shot looking upwards and further in.
I suspect the weight normally holds an overflow door closed and the cylinder is a float that opens the door. Or it could be a flood gauge. The cylinder flips a switch that somewhere indicates the drain is flooding.
All speculation of course. Which drain is it in? Or Which suburb is the drain in? Please don't advise the exact location.
Correct, it's a float for the sewer flap. There are quite a few of these around but this is quite an old one.

As for lack of smell, pop the hatch and catch a whiff

There's the chance it hasn't operated in a very long time, so no guarantee you'll get any stench...

The one at the outfall of Dwellers' Tomb is probably the most active I've encountered... yuck.

I didn't poke my head in this one, but I did on one of the cleaner ones further up and you could get a good look of the system in there, that's when i got a bit of smell but it just didn't seem strong enough to be crap but hey I suppose that's a good thing.

That said though my neighbour recently opened the pits out the front of my house.
Long story but he had a blockage and wanted to put the hose in my stormwater pit in the backyard to see how mine was flowing as we share a single stormwater drain (apparently anyway, due to shitty subdivision).
So he opens both lids in search of the stormwater, and the first one he opened was sewer, again no smell? but he wasn't sure it was sewer, I had to point out the "-S" on the lid (MMBW-S) meant it was sewer. So he opens the one next to it, proceeds to leave the sewer lid off in the middle of the footpath, with no bollards or gates and a 2 meter drop straight into a sewer pit. I stuck around to make it as safe I could but wow some people are dumb. He didn't even need the sewer open, just left it open till he was done looking in the stormwater pit.
[/quote]
Interesting that sewage doesn't smell much like poo. I think most of it is actually detergent and other wastes.

There are a few shafts that seem to have no smell at all, I assume it's because they're either rarely used (supplanted by newer sections) or abandoned altogether. I once had a go at climbing down one that was fairly well ventilated (it was old and made of redbrick, and interestingly took stormwater too). It went down a couple of storeys, and I got all of these microscopic cuts on my fingers that took some time to heal. Highly recommend not doing it.

Another way to distinguish between sewer and stormwater drain manholes - stormwater ones tend to have slits in the top for ventilation or are internally reinforced concrete (as opposed to the cast-iron grid ones you need a lifting key for).