I'm with El. The photo reminds me of the photo in Grandpa's Engineer's Handbook that showed a 4-4-0
that exploded at 110#s while standing in a station. Front end opened up like the Cuban engine did.
Crown sheet explosions frequently resulted in the boiler leaving the frame completely. Sometimes they went some distance. Other times they were relatively minor. Early in Dad's RR career he was
braking the head end. The fireman had just put in a fire and got on his seat just ahead of Dad when the crown sheet buckled. The blast blew every lump of coal out of the tender but the crew had only minor injuries.
It was a "Q" engine but I don't know what class or number. Something else I wish I had asked him more about! Jim