The new green machines are on their way to Southampton Container Terminals as part of the latest multi-million-pound investment in new equipment.

SCT has ordered 11 straddle carriers from Noell Crane Systems of Germany, which will be the first of its make to be used at the terminals.

The twin lift machines will be more environmental friendly, conforming to tough European emissions requirements.

The change in supplier results from a preference for diesel electric machines over diesel hydraulic.

SCT's head of engineering, Cameron Waugh, said: "The new machines run on AC electrical drives, which we believe is the way ahead.

"They are more reliable and will therefore lead to reduced operating costs."

The machines will replace 11 older straddle carriers and are part of an overall order for 25 new carriers that will be implemented over the next two years.

Ultimately, the greater reliability of the diesel electric units will lead to 31 older machines being phased out of service.

Visually, the Noell machines will be most notable for having their Mercedes engine mounted at the top rather than just above ground level where maintenance is more difficult.

Steel wire rope hoists will provide a twin lift capability for two 20ft containers weighing up to 50 tonnes or individual 40ft or 20ft units weighing up to 40 tonnes.

Hoist speeds will be 24 metres per minute, while over-groundspeeds, dependent on load weight, will be up to 30km per hour.

"The new machines will also be good for the environment in that oil volumes will be less, fuel consumption should be better and emission levels will be lower, conforming to Euro 2 exhaust emission standard,'' said Mr Waugh.

"In addition, drivers will benefit from enhanced ergonomics and air conditioning.''

The new machines will be erected on site starting in May and should be fully operational by the end of August.