INTRO: Italian Railways and Nord Milano Railway are about to put into service a fleet of 50 double-deck EMUs for the cross-city Passante route; each high-capacity TAF trainset will carry up to 848 passengers in air-conditioned comfort

BYLINE: Ing Giancarlo Piro

Tony Traina

Strategic Business UnitRolling Stock & Traction DivisionItalian Railways

IN A 10-year rolling stock replacement programme drawn up in 1991, Italian Railways’ Local Transport Division envisaged deploying a range of new vehicles on its busiest urban networks. First of these is the high-capacity TAF trainset capable of carrying over 800 passengers in four cars, and the lead unit is now undergoing tests.

Technical specifications for the double-deck TAF (Treno Alta Frequentazione - High Occupancy Train) electric multiple-unit were prepared by the FS Rolling Stock Division for procurement in line with European Union directives. Following receipt of tenders from five groups, a contract to build 40 trains for FS and 10 units for Nord Milano Railway (FNM) was awarded in July 1994 to a consortium of Breda, Ansaldo Trasporti, ABB Tecnomasio (now Adtranz Italy) and Firema Trasporti.

The first TAF EMUs are to be deployed on Milano’s cross-city Passante route (RG 1.92 p40), to be operated jointly by FS and FNM. It is expected that a further nine will be ordered by FNM, and FS anticipates that an additional batch of 13 TAFs will be required for service in other cities.

Improving mobility

With bodyshells constructed from thin-walled aluminium alloy extrusions, each 104m TAF trainset comprises two trailers between two power cars with cabs. Each car has two vestibules, located inside the bogies to give a floor height of 650mm for level boarding from high platforms.

Facing pairs of seats are arranged in a 2+2 configuration throughout the train, on the upper and lower decks and in saloons over the bogies with 24 seats. Styled by Pininfarina, each set has 475 seats and room for 372 standing passengers, excluding 14 folding seats in the vestibules.

Each motor car has a retention toilet on the lower deck, installed as a complete module, and one motor car in each set has a space for a passenger in a wheelchair on the lower deck. In place of a step, a short ramp leads down from the inner vestibule, and the toilet is fully accessible. The vestibule is equipped with passenger-activated retractable ramps at the doorways to bridge the gap between train and platform.

TAF units will have in-car passenger information systems combining visual displays with automatic announcements; external destination indicators are also planned for the car sides. Passenger saloons and driving cabs are fully air-conditioned, with environmentally-friendly coolant specified for the climate-control equipment. Fire-control systems fitted to the TAF use a similarly ’green’ suppressant and water-based paints have been used throughout the construction process.

Traction equipment

A pantograph is located with the rest of the electrical equipment behind the cab of each end car over the single motor bogie. The power cars are connected by a high-voltage train line feeding the modular GTO-based drive. Traction current passes through water-cooled chopper and inverter stages to the two three-phase asynchronous traction motors on each motor bogie. The databus-based train control and monitoring system incorporates a diagnostic function.

The TAF EMU is configured for regenerative braking, and chopper-controlled rheostatic braking is also fitted. Auxiliary power is provided by a static converter with an output of 670V 50Hz, and transformers supply the train line at 380V 50Hz.

Each motor bogie has two brake discs, and each trailer bogie six discs. The H-shaped bogie frames are constructed from welded steel sections, with coil spring primary suspension and air-sprung secondary suspension.

Bidders for the TAF order were asked to present an assessment of the whole-life cost of their proposed train, factoring in maintenance requirements. The winning design is expected to operate 200000 km annually over a 36-year service life, managing 3·6 x 106 km between major overhauls. o

Trainset details

Length over couplers mm 103 970

Length of motor car mm 25895

Length of trailer car mm 26090

Motor bogie wheelbase mm 2750

Trailer bogie wheelbase mm 2550

Seating capacity 475

Standing capacity 372

(at four passengers per m2)

Weight tonnes 210

Maximum speed km/h 140

Maximum output at wheelrim kW 3640

Power supply 3 kV DC

Maximum starting tractive effort kN 214

Number of powered axles 4