Re: Are those ovens standard commercial ovens?
Items for use on ships or aircraft must be tested for various things which don't apply necessarily to shore bases - for example:
1. Power draw - yes ovens take a lot of power, but you have a limited power budget on board a small ship or an aircraft so you must be sure that your equipment doesn't go outside of it's rated range.
b.) Flammability - fires on ships or aircraft are a lot worse than on a shore base so you need to make sure they are made out of the least flammable components possible for their application and that they are much less likely than shore-based equipment to start a fire in the first place. For ships you also don't want them to behave unexpectedly when they become submerged in water in the event of a flood.
♣) Stability - because ships and aircraft move around a lot you don't want the oven or the shelves or the food on the shelves to move or fall out of the oven when the door is opened etc - barring earthquakes this isn't a consideration on land bases.