Cast iron plates for bridge over burn channel?

In the "Research Needed and Experiments" section of RMH, one of the wish-list items was "Increased durability of ...the bridge over the burn tunnel."

In my area, railway base plates are readily available, being simply discarded along the tracks after replacement. These are cast iron plates about 8"x 5" x 1".

They do have holes for spikes, but I imagine these could be filled in with clay, and bricks layered over top.

They are heavy for their size, around 8 lbs.

Picture attached, below.


Is this a reasonable alternative, or a recipe for trouble?

If firebrick fails, I don't think those plates will last either.

They would be extremely valuable in other areas, though. Making a grate and feed tunnel liner (easily removed and replaced) to protect the firebrick from erosion and damage. As mass in the bench. Maybe a few placed as hotplates in areas of the exhaust--for different temps--slide your pan from one to the other to go from high to low to keep warm...

If they are free for the taking, take them. But make sure, as the railroad usually gets really mad about people taking stuff they still wanted.

R Scott wrote:If firebrick fails, I don't think those plates will last either.

They would be extremely valuable in other areas, though. Making a grate and feed tunnel liner (easily removed and replaced) to protect the firebrick from erosion and damage. As mass in the bench. Maybe a few placed as hotplates in areas of the exhaust--for different temps--slide your pan from one to the other to go from high to low to keep warm...

Love the hotplate idea - I've seen this done over the burn tunnel on top of the firebrick.

R Scott wrote:If they are free for the taking, take them. But make sure, as the railroad usually gets really mad about people taking stuff they still wanted.

They are waste output that's cheaper to leave in-place than dispose of, but not necessarily free either. It's not exactly theft, but more like recycling without consent The area bordering the tracks are policed, but theres' just too much track for them to be everywhere all the time.

Living near the tracks, I can get as many as I can carry, but sadly have never been able to think of a good use for these.

Hotplate.... that is a great idea though.

The melting point of iron is 2800F, but what you won't be able to see happening is the small amount of oxidation that will occur, in between burns, when ambient moisture in the air condenses on the plates. This surface oxidation will then get blasted off during the next burn cycle, losing a little bit of iron every time. But hey, at an inch thick, they may last for quite a while before burning out.

My fantasy material for a burn channel and heat riser lining would be crucible-grade porcelain, at least an inch thick....dreamy

Chris Burge wrote:The melting point of iron is 2800F, but what you won't be able to see happening is the small amount of oxidation that will occur, in between burns, when ambient moisture in the air condenses on the plates. This surface oxidation will then get blasted off during the next burn cycle, losing a little bit of iron every time. But hey, at an inch thick, they may last for quite a while before burning out.

My fantasy material for a burn channel and heat riser lining would be crucible-grade porcelain, at least an inch thick....dreamy

I guess ultimately, there's two considerations: Of one durability, and the other of performance. It sounds like these plates do degrade, but would that be slower or faster than the Firebrick in this location?

I speculate there would be a performance benefit, due to the Steel's ability to heat up and give back faster. Any thought?

Tyrone Slothrop wrote:
I guess ultimately, there's two considerations: Of one durability, and the other of performance. It sounds like these plates do degrade, but would that be slower or faster than the Firebrick in this location?

I speculate there would be a performance benefit, due to the Steel's ability to heat up and give back faster. Any thought?

Another thing you may want to consider is how much, and at what rate, the plates will expand and contract during the heating/cooling process, putting stress on the surrounding brick, potentially creating small airgaps at the metal/masonry joints.

Ah this is what I was worried about in my thread "all metal RMH?" I have access to all sorts of metal but it looks like its only useful in certain areas. do you think even at one inch it would be replaced before fire brick?