Six hearth engines and 40 firefighters have been known as to the location on North Woolwich Highway in Silvertown.
Round 25 staff left the location earlier than the London Hearth Brigade arrived. There have been no stories of any accidents.
Station Commander Daniel Capon, who was on the scene, mentioned: “Entry to the hearth was difficult, with firefighters working to succeed in a sub-surface conveyor belt.
“Crews labored extremely exhausting to carry the hearth beneath management.”