When is a fireboat a tug? When is a tug a fireboat? The fitting of fire-fighting capacity on harbour tugs is very common, but typically those installations are limited to up to the capacity of the Class Society Fi-Fi 1 designations with a total pump capacity of 2,400 m3/hour. However when an Owner requires a major terminal support tug with significant towing and ship-handling capabilities, AND a Fire-Fighting II capability of 8,400 m3/hour, the result is an exciting combination of the best attributes of both vessel types. Robert Allan Ltd.