numbered 458001–458030, were manufactured at the former Metro-Cammell works at Washwood Heath in Birmingham, which Alstom had acquired in 1989. Each unit was formed of two motor cars with driver's cabs, an intermediate trailer car, and an intermediate motor car. Both driving cars had small sections of first-class seating, while the intermediate cars were all standard class. The trailer car was provided with a pantograph well and space for an alternating-current transformer, enabling conversion to overhead-line operation if required at a later date. One bogie on each motor car was fitted with traction motors, for a total of 6 motors along the train, a maximum speed of , and a cumulative power output of . Both driving cars were also provided with end gangways, with the intent of allowing passengers and crew to move between coupled units. They are the only members of the Juniper family to have such provision. The first unit, 458001, was delivered to SWT for pre-acceptance testing on 31 October 1998. Attempts to place the new class into passenger service were beset by delays and major technical problems. The roofs of the new trains leaked, allowing water ingress to both the driver's cabs and passenger saloons. Onboard electronics repeatedly failed, affecting the air-conditioning and traction systems, and the Train Management System (TMS) software also proved to be unreliable. More problems were encountered in coupling process and the design of the end gangwaysexisting practice with ex-BR stock taught that units could be coupled or uncoupled in the space of just a few minutes, but the Juniper gangway design was significantly more complex and took far longer to operate. Additionally, the entire TMS had to be restarted whenever units were coupled and uncoupled, which meant that the total time taken to couple or uncouple Class 458 units could reach up to 30 minutes. Both of these facts in particular remained considerable limitations on the use of the new fleet; ultimately SWT had no choice but to treat the Junipers as being semi-permanently coupled in pairs. The first Class 458 passenger service eventually ran on 25 February 2000, but even then only two units (458004 and 458005) were available for use. By March 2002 twenty-four of the thirty units had been delivered, but on an average day only nine to ten units were actually available for service. The last six units eventually arrived by October 2002, but it was