Stephenson's rocket firebox

[PaxmanValenta]

Hi
Was the firebox on the Rocket surrounded by a jacket of water like on later steam locomotives? If not would the metal not have got too hot?

 

[John Webb]

As far as I am aware, the only boilers without the firebox built into them were those used for powering early stationary beam engines; they were mounted on brick walls with the fire lit underneath them.

I am uncertain when the first boiler with the firebox built in and surrounded by water was developed, but I suspect that was also land-based and was needed when the beam engines got bigger and more steam had to be generated. So I think all locos from Trevithick onwards had boilers where the majority of the firebox was surrounded by water.

John Webb

 

[2392]

Hi
Was the firebox on the Rocket surrounded by a jacket of water like on later steam locomotives? If not would the metal not have got too hot?

In short yes. Though to go into further detail, you will note that there is/are a couple of short copper pipes from the boiler barrel into the top of the 'box and a pair one either side that run back to the under/lower sides of the barrel to return the water from this "jacket". Ok on later engines the firebox was almost an extension of the barrel so didn't need the pipes. I'm pretty sure if you were to google Stephenson's' Rocket or go to the NRM web site you'd be able to get hold of a picture or two showing the arrangements in general.