Sentence:  They make a patent rockcutter fo excavating rock under water without explosives, bucket dredgers and suction dredgers of all types, suction hopper dredgers with Robinson cutter for clay,  suction plant for pumping out barges alongside, <WSD>longshoot</WSD> dredgers, hopper barges of all kinds, gold, tin and platinum dredgers, dipper dredgers, sternwheel steamers, lighters and barges, floating plant of every description, either launched or in pieces for shipment, and spare parts or renewals for any of the above. 
Meaning of the word marked with <WSD> tags:  A type of dredger that ejects sand and sediment through a long stream.