Fitted with high-density 2+3 seating, they were typically used on short distance interurban services from Melbourne to Bacchus Marsh and Geelong until their withdrawal in 2024.

By 1983, the 1981 New Deal had been such a success that the incoming Cain Government ordered conversion of a fleet of the early Harris suburban Electric Multiple Units to replace the last of the older wooden carriage stock.

For the purpose of contract negotiations, short cars were referred to as SCH, SH or STH and long as LCH, LH or LTH, respectively for conductor, regular and terminal carriages.

Following withdrawal of the Tulloch fleet around 1994, the four MTH carriages (63 seats each) were used on the non-electrified suburban Stony Point line, hauled by whatever locomotives V/Line (later V/Line Passenger) had spare at the time.

Typically, two carriages would be used on weekdays and a third kept at Frankston for additional weekend capacity, with the fourth under routine maintenance in the city.

The contract was awarded to Clyde Engineering, and the initial plan was to convert 33 Harris cars to 11 semi-permanently coupled sets of BCH-BH-BTH.

[15] During the long weekend holidays, H sets would occasionally be extended from Shepparton to Cobram as higher capacity rollingstock was needed elsewhere.

Otherwise, for events like football matches and the biannual runs to Lara for the Australian International Airshow at Avalon Airport, trains would be formed with nine carriages, a locomotive on each end and another between sets, near the middle.

Because of the underfloor multiple-unit cabling, all locomotives on the train would work together from a single control stand; but each set of carriages was powered by its nearest P class locomotive because the power cables, for things like lighting and airconditioning, were only designed for a maximum electrical load equivalent to four carriages.

When hauled by other classes of locomotives or if the HEP failed, a separate power van was coupled to the set to provide that same function.

The MTH cars could be hauled by anything and everything, because they had onboard alternators negating the requirement for any sort of external power supply.

To prepare for a then-planned order for high speed country trains, in 1986 set LH33 (BTH173-BH153-BCH133) was fitted with Socimi bogies designed for operation at 160 km/h (99 mph).

The set was hauled by locomotive A85 on runs between Glenorchy and Lubeck on the main Melbourne to Adelaide line, starting from Wednesday 23 July 1986.

The order also featured two more BCH conductor carriages, though these were fitted with smaller vans and an additional ten seats, compared to their predecessors.

These final carriages were converted from previously refurbished "Grey Ghost" Harris stock, rather than the original blue cars.

However, it was decided to instead operate the MTH carriages exclusively on the Stony Point route, because an infrequent, isolated shuttle service would have been a waste of one of the N or P class locomotives with head-end power, better used elsewhere.

If the Stony Point line had run from Spencer Street in lieu of Frankston, then it is quite possible that the H fleet would have been reworked with thirteen FSH and two LH sets (plus one spare carriage), all with about 250 seats.

When the five-carriage sets were formed, the end BTH and BCH cars were recabled with higher-capacity wiring, to avoid any risk of overheating.

These services became colloquially known as the "Poor Man's XPT", with a P class locomotive on each end of the consist, controlled by a single crew.

These trains usually provided peak-hour services to Bacchus Marsh, Wyndham Vale and Seymour, hauled by N and P class locomotives.

[25] In January 2021, H sets were re-rostered exclusively on the Bacchus Marsh[26] and Shepparton[27] lines, alongside occasional unscheduled runs to Geelong and elsewhere.

[28] In the era after Covid significant quantities of VLocity carriages were delivered; this in conjunction with the general replacement of locomotive-hauled trains across the board led to some minor set reconfigurations.

On 26 July 2023 a train hauled by N Class locomotives N465 and N460 transferred H sets SSH28 and SSH27 to Shepparton for storage;[29] these had returned to Newport by November for disposal.