coaledsweat wrote:It appears to be a water tube, coal fired steam boiler.
It is a water tube, steam boiler. The presence of the tubes in the firebox make it a tube boiler and the water in the tubes (as opposed to fire= firetube) makes it a watertube boiler. Note the sight glass at the right front at the top. The water must be in that sightglass and the tubes you see inside are filled at least to some point in the bottom half of the sightglass. The headspace above the waterline allows it to make steam.
Water tube boilers are more expensive and more efficient than firetube boilers.