Does anyone recognize this canister connected to shower drain line?

[d-marbles]

I'm hoping someone can identify this cast iron canister connected to the drain line of a stand-up shower in a house built in the 1940's, it's about 5.5 inches (14cm) tall, has a removable top and has no markings that I can see. I wouldn't bother, but the drain began leaking and I need to know it's purpose so I can update it if needed. The photos are taken from the basement below, drain from shower on the right, then down to can, and up again to wherever the drain goes. Thank you.

 

[d-marbles]

After thinking about it more, I assume it must be a one way valve to keep sewage from coming up the shower. What would you guys recommend instead?

 

[Jeff Handy]

Looks like a drum trap, an old style of trap.
Pretty common to see them on old tubs.
That cover with the big square nut is meant to unscrew, for cleaning it out, but they are almost always rusted shut, or at least the leverage needed to unscrew it would bust up the pipes.
You can cut that thing off, and tie in a new pvc p trap, attached to the old metal drains with shielded couplings.

 

[d-marbles]

Looks like a drum tram, an old style of trap.
Pretty common to see them on old tubs.
That cover with the big square nut is meant to unscrew, for cleaning it out, but they are almost always rusted shut, or at least the leverage needed to unscrew it would bust up the pipes.
You can cut that thing off, and tie in a new pvc p trap, attached to the old metal drains with shielded couplings.

Thank you Jeff Handy ! I googled "drum trap" and there are a bunch of photos that look just like mine, mystery solved! I will replace it as you recommend. Thanks for taking the time to reply.

 

[Jeff Handy]

Maybe some pros on here can make a quick diagram of how to best pipe in a new p trap in there?
Or you can usually find good vids on Youtube.

 

[HWSleuth]

That’s a “drum trap.” That’s an antique! Would love to have it to add to my collection. Have you removed the trap’s top? These were used in Texas 75+ years ago for p-traps on bath tubs. Be sure and check the trap’s contents, we usually found jewelry or old coins when the traps were replaced. Obviously never enough to be worth anything toward retirement.

 

[d-marbles]

That’s a “drum trap.” That’s an antique! Would love to have it to add to my collection. Have you removed the trap’s top? These were used in Texas 75+ years ago for p-traps on bath tubs. Be sure and check the trap’s contents, we usually found jewelry or old coins when the traps were replaced. Obviously never enough to be worth anything toward retirement.

Thanks for replying! You really collect old plumbing? I decided not to replace it, since i (hopefully) didn't have to remove anything. If my quick, caulk fix of the shower drain leaks, I will likely be getting a new trap, and you'd be welcome to it, provided you pay for shipping and weren't joking. Thanks again. -and no, I didn't try opening it either, the shower stall above has always had a screw down screen plate, so it's unlikely any jewelry got through.