The paper describes the electrical equipment which was applied to the construction of a large bridge across a tidal river.The difficulties which arose are discussed, and suggestions are made with a view to overcoming these difficulties in future constructional work of this nature.The method of supplying energy to the sinking sets is given, and it is suggested that this might affect the design of submarine cables for tropical waters where the teredo worm is known to exist.The paper concludes with particulars of the amount and cost of the electrical energy consumed, together with a curve showing the consumption of electrical energy during the constructional period.