[citation needed] Two major types of carriage were constructed - thirteen AZ first class cars with closely spaced but smaller windows, and twelve BZ second class cars with wider spaced but larger windows (the thirteenth BZ entered service on standard gauge).

A single twinette sleeping car was also built in a Z type body shell, entering service in 1963; it had 20 berths.

[citation needed] A number of carriages were placed onto standard gauge bogies from 1962 for use on interstate trains such as the Spirit of Progress.

The Z type cars were made redundant by the early 1990s with the introduction of the Sprinter railcars, most Z Sets were broken up, with the formation of West Coast Railway effective Sunday 19 September 1993 to run Melbourne ~ Geelong ~ Warrnambool Passenger Rail Services under contract to the Victorian Governments Dept.

V/Line maintained ACZ 257 (now reclassed as BCZ 257 ~ an economy class carriage, with the WCR 2001-era upgraded conductors work station / compartment) now reversed to be at the West End, while still maintaining its Z type interior as modified & refurbished by WCR in their DDA-compliance upgrade of 2001.

(As part of these upgrades for DDA-Complience by WCR: ACZ's 252 & 257 were permanently turned, with the old east end {that once formerly housed the 1980s-era fitted larger conductors work station / compartments} being subsequently removed & replaced with a DDA-complement disabled toilet, similar to that fitted to V/Line BZN Carriages, this was hence renamed the new west end of the carriage.

The remaining Z type carriages in the V/Line fleet were temporarily removed from service in January 2013 due to cracking occurring in the bogies.

[4][5][6] The first S and O/J type carriages were designed with full-width diaphragms in mind, using steel plates to give the impression of a single-unit train.

[7][8] The remainder of the class was built with chamfered edges to the body, and all units had exposed rubber diaphragms fitted from new.

[citation needed] The earlier cars in each set had a single tank for 140 gallons of cold water, and small air-intake panels either side of the end-of-carriage diaphragms.

[citation needed] All the broad gauge cars except AZ2, BZ1 and BZ2 were powered via Hypoid motor-generator sets, with a gear ratio of 3.47:1 generating 17 kW.

The remaining three cars used an alternative system with a 2:57 gear ratio, driving a separate generator set to provide the same 17 kW.

Cars AZ3 and BZ3 were modified to allow quick conversion to standard gauge if needed, and to match most of the stock on the Sydney run they were fitted with laminex interiors in lieu.

From the 1980s the cars were gradually converted and upgraded to suit the requirements of the New Deal, and the fleet was renumbered as part of that project to match the new reservations and rolling stock management systems.

Between 1995-1997 these six cars were refitted internally, with a larger door at one end and seats respaced, to provide sitting for 76 passengers and a parking space for one wheelchair.

This had been applied to BCZ263 in the previous year, and used the carriage shell with a new interior identical to that of the BN cars, with 88 seats in a 2+3 format and no special functions.

BZ269 was stripped by Steamrail, renumbered BZ6 and named Hobsons Bay, and now operates as a function car with a bar serving drinks, but otherwise a large open space with no seating provided.

Introduction of the Sprinter fleet from 1993 rendered some of the regional loco-hauled carriage sets obsolete, so the vehicles were withdrawn and stored, typically at Ballarat or Bendigo workshops; and three (252, 255, 257) were sold to West Coast Railway when that company gained operational accreditation.

ACZ260 was supposed to be included in the sale but was damaged a few days before the handover; it had been stored at Newport Workshops for 22 years, before rebuilt by V/line in 2017-18 to become a power van for the Albury standard gauge service.

As patronage increased approaching the new millennium they were gradually called back into service, and converted to provide additional Economy seating capacity.

Many of these were rotated and attached to the west end of existing sets, rather than reforming their previous consists, to provide a temporary facility for wheelchair storage following passage of the Disability Discrimination Act in 1992.

BCZ262 was converted to the BZN format in 2008,[13] and BCZ259 to BTN259 followed in 2013,[14] leaving only BCZ257; this vehicle was used to form set Z57 when additional capacity was required on the Geelong line, and in more recent times it has been utilised as a secondary luggage storage area, attached to one of the regular N sets, often rostered to run to Swan Hill where the reduced capacity is manageable, and the increased comfort appreciated.

The car was fitted with marker lights, backup lamp brackets and tail discs at both ends, allowing it to trail any train.

[16] It was converted to standard gauge for use on the Albury line, then in 2022 the carriage was transferred to the Seymour Railway Heritage Centre and reclassified 10PZ, in line with its pre-New Deal identity of 10AZ Initially, AZ and BZ cars were allocated to long-distance passenger trains in Victoria.

Cars would be attached to The Vinelander for Mildura, The Gippslander to Bairnsdale, the Great Northern to Swan Hill and also to Albury.

At this time the thirteenth BZ-type shell was still under construction and it caught fire on the production line, so 8BZ was quickly modified and was made available for standard gauge service in February 1962.

In the early 1990s the six VFK cars were returned to broad gauge and refitted internally with a better type of seating, being coded BZS to differentiate them from the existing BZ class.

Cars rebuilt like this were coded BZN or BTN, depending on whether they were intended to be used as fourth or fifth carriages as attached to an N set.

On Thursday 22 September 2016 a test train ran from Melbourne to Geelong and back, with two locomotives, set N11 at the west end and BZN cars 271, 267, 274 and 252.

Initially the V/Line logos were covered with white "W" decals, and after the sale was completed on 9 April 1995, the cars were repainted into that company's blue scheme.