The engineering team at Voith have been carrying out a careful review of all their products in recent years and considerable improvements have been made to Voith cycloidal propellers to try to close the 'performance gap' between vessels with ASD propulsion and Voith systems in terms of horsepower per ton of bollard pull. That programme has delivered many significant improvements in unit design and engineering, including new blade profiles and lengths, improvements to protection plates and hull design. Much of this work has come to fruition in new tractor tug designs.

Two of the latest vessels in this category are the tugs Svezia and Inghilterra, recently completed for the Italian tug company Rimorchiatori Riuniti Spa of Genoa by Cantieri Navali Termoli Spa. Both tugs are built to a design by Canadian naval architect Robert Allan and equipped to carry out escort and shiphandling duties. A fire-fighting system is fitted to comply with FiFi 1 standards along with oil recovery capacity and sufficient salvage gear to enable assistance to be provided in an emergency. The vessels are classed by RINA, with the following notation - FiFi 1 with water spray, Oil-Rec, AUT-UMS, Escort Tug.

Svezia (Sweden) and Inghilterra (England) are vessels of just 27.50m in length overall with a moulded breadth of 11.50m, a maximum draft of 6.00m and measuring 298 gt. Twin Voith Schneider size 30 R5/245 propulsion units, each with five blades in a 3.0m orbit, are installed in the normal configuration beneath the bow.

The units are powered by two Wartsila 6L26A diesels each generating 2,060kW at 1,000rev/min, a total of 5,603bhp. On trials the first tug, Inghilterra, achieved a maximum bollard pull of 70 tons and maximum free running speed of 13.5 knots, with an economical cruising speed of 10 knots.

Each vessel is fitted with a hydraulically powered Rolls-Royce/ Rauma Brattvaag TW 1500/750H double drum towing winch. Both drums have a maximum brake holding capacity of 150 tons and can accommodate a 250m towline, one for escort work and one for general shiphandling.

A hydraulic knuckle boom crane is situated on the after deck adjacent to the winch for handling stores, towing gear and pollution control equipment.

The fire fighting system is based around a pair of remotely controlled monitors above the wheelhouse roof, each with a capacity of 1,400m 3/hr. A salvage pump with a capacity of 350m 3/hr is provided and can operate with a maximum head of 3m. The oil skimmer supplied is a Lamor type LMS/PDWD with a recovery capacity of 50m 3of recovered oil can be stored onboard in dedicated tanks.

The pollution control package includes 200m of Mannesman floating boom suitable for coastal operation.

The wheelhouse style is typical of a Robert Allan design and affords good visibility with a compact layout. Navigation equipment is installed to seagoing standard and meets the requirements of GMDSS Sea Area 1. Fully air conditioned accommodation is provided for a maximum (under SOLAS rules) of 10 persons.