The Mark 2D to 2F classes, built from 1971 onwards, had air conditioning and could be distinguished from earlier sub-classes by having sheet glass windows.

This means that British Rail rolling stock like the Mark 2 carriage can run on most New Zealand lines after gauge conversion.

Eight were extensively refurbished for the Wellington–Palmerston North Capital Connection, classified S (for Scenic), with new Japanese bogies and new auto plug doors and interiors.

In late 2009, all S, SE and SW carriages were required to be modified so that their pneumatically operated interior doors open automatically if the compressed air supply is lost.

The doors stuck in position, and three people were required to open them manually, sparking safety concerns that the carriages could not be evacuated quickly in the event of a fire.

These were the first British Railways Mark 2 carriage rebuilds, and they retain the original window configuration and curved Corten-steel vestibule ends.

[4] They were operated as a single consist by Tranz Metro on peak express services top-and-tailed by EO class electric locomotives.

There are four SE, one SES and one SEG carriages, which received a less thorough rebuild than the SWs and retain their BR airline-style seating.

In November 2011, they were taken out of service due to frequent faults of the run-down electric locomotives pulling them[5] and the availability of sufficient Matangi units to replace them.

They were criticised by train users for their smaller seat pitch, poor lighting, and lack of tray tables and power outlets.

[10][dead link‍][11][12] From March 2018, three SA carriages were overhauled and converted into luggage vans for KiwiRail division Great Journeys New Zealand.

Trains set off at Frankton, stopping at the new Rotokauri Transport Hub and Huntly station, before reaching Papakura.

The carriage had been reskinned removing windows and one set of metro styled doors at one end, painted in Great Journeys New Zealand colour scheme, but retained its former designation as SA 6112 while finishing work was undertaken.

[citation needed] The seven surviving S (Scenic) carriages previously operated on KiwiRail's Capital Connection service between Wellington and Palmerston North between 1999 and 2023 were put up for tender and in 2024 and sold to the Pounamu Tourism Group and relocated to Dunedin for refurbishment.

These were the first British Railways Mark 2 carriage rebuilds in New Zealand, and they retain the original window configuration and curved Corten-steel vestibule ends.

The balance of nine SAs SA5638, SA5770, SA5703, SA5818, SA5743, SA5829, SA5617, SA5695 and SA5730 were railed north by Glenbrook Vintage Railway's DBR1254, along with two SDs for Steam Incorporated for storage at Mission Bush 27 August 2024.

With very few options available, Welch purchased ex Virgin Trains West Coast Mark 2F FO 3433 and TSOs 5915/5939/6419, arriving later that year at the Port of Auckland.

In 2008, Welch purchased four ex Virgin and five ex-Gatwick Express coaches from Angel Trains and Porterbrook, arriving at the port of Auckland in 2008 and trucked to Hutt Workshops for storage.

As at August 2014, this ETCS equipment has been removed, and the cab instruments reverted to the standard layout, and ETP installed.

[29] As of March 2021[update], there were 28 SA/SDs and 6 SX carriages remaining, which are currently stored at the KiwiRail Taumaranui railway yard.

Auckland Transport's financial team confirmed that if AT were to write off the carriages, AT would be able to offer them to KiwiRail, Octagonal and the Glenbrook Vintage Railway.

The write off and offer to sell for a dollar each is to offset the ongoing costs that were being incurred by AT annually to store the 34 carriages.

9x SA and 4x SD carriages purchased by RES as follows: SA5638, SA5770, SA5703, SA5818, SA5743, SA5829, SA5617, SA5695, SA5730, SD3199, SD5652, SD5762, SD5842[31] The four GVR SDs, SD3199, SD5652, SD5762 and SD5842, were railed north to Glenbrook on 9 July 2024.

The balance of nine SAs SA5638, SA5770, SA5703, SA5818, SA5743, SA5829, SA5617, SA5695 and SA5730 were railed north by Glenbrook Vintage Railway's DBR1254, along with two SDs for Steam Incorporated for storage at Mission Bush 27 August 2024.

[32] Three SD bodies were onsold by Mainline Steam for private use, minus bogies and generators, and are located at C&R Developments Ltd – a mining vehicle contractor and builder in Hannon Road, Hautapu, Cambridge in the North Island of New Zealand.

After a campaign by Taumarunui locals and the Ruapehu District Council for the removal of the heavily graffitied carriages, KiwiRail scrapped 27 of the carriages in March 2024 as they were equipped with older, x28020plus coil spring suspension bogies that were "less suitable" for re-use, the 40+ year old bogies had come from former NZR FM guards vans.

Twenty-six carriages will remain on site: Eleven belong to KiwiRail, 15 to Glenbrook Vintage Railway, and two for Steam Incorporated and a single SA was purchased for the Taumarunui Rail Action Centre by one its members, preventing its scrapping and it is now on display.

[33] During 2018, 31 SA and SD class formerly used in Auckland sets were purchased by the Antipodean Explorer company and transported from storage in Taumarunui to Dunedin by KiwiRail for refurbishment into a luxury train at the former Hillside Railway Workshops.

During mid-March 2024 KiwiRail scrapped 27 carriages in Taumarunui as they were equipped with older, x28020plus coil spring suspension bogies that were "less suitable" for re-use.

[33] In September 2024, SD5675 and SD5883 were railed to the Glenbrook Vintage Railway and then quickly parted out for bogies, generators and electronics by Steam Incorporated.