Departing Birmingham Snow Hill with the 2K27 from Dorridge to Kidderminster is London Midland Class 172, 172337.
The Turbostar units have become one of the most vital parts of the post-privatisation scene on the UK network, operating on a majority of the country's higher capacity routes.
The roots of the Class essentially go back to the Networkers of the early 1990's. Ordered by Network SouthEast, these units, which comprised of the diesel Class 165 and 166, were constructed to kill off the ancient railcars and units of the 1950's. With a promising order on the go, this was brought to an abrupt halt by privatisation, whereupon Network SouthEast was killed off and replaced by a selection of franchises based in the London area. Whilst routes these units were proposed to be introduced on were subsequently scrapped, the new operators of the Chiltern Mainline, Chiltern Railways, maintained their order, and took on what was known as the Class 168 'Clubman' units, which began operation from 1998 in a style similar to that of the previous Class 165's.
However, Adtranz intended to improve the breed with a new and more futuristic style. In conjunction with the Class 357 'Electrostar' equivalent, a prototype trailer car rebuilt from a 4-CIG unit was unveiled in 1997 to highlight their new look. This was followed in 1998 by the arrival of the Class 170, originally ordered by Midland Mainline to work semi-fast operations out of London St Pancras to Leicester, Derby and Nottingham. Later operators of the Class 170 were Central Trains in 1999, who operated them across the Midlands and on longer distance trains into Wales and to Yorkshire, Anglia Railways, working on the Great Eastern around Ipswich, Norwich and Cambridge, Southwest Trains, which used their small fleet on trains from London Waterloo to Salisbury and Yeovil Junction, and Scotrail, working the premier commuter service between Glasgow and Edinburgh, as well as other longer distance trains. This coincided with a second batch of Class 168's built in the same style that were introduced between 2000 and 2004.
In total, 122 Class 170's were built between 1998 and 2005, together with 19 Class 168's, 13 in the original style, and 6 in the new. Together these units dominated many of the longer distance semi-fast and express trains on the UK mainline network, but their success was far from over.
In 2003, to replace the ageing 'Hastings' Units on the Marshlink and Uckfield Lines, 16 Class 171's were released in 2003 to improve the reliability of this often forgotten route. Working between Brighton and Ashford, these trains have revolutionized operations on the line, and continue to maintain a high standard of work even today.
But again this wasn't the end, as in 2010 yet another member of the Turbostar family was introduced in the form of the Class 172. Class 172's were built to work between three operators, London Midland, Chiltern Railways and London Overground. Chiltern and Overground Class 172's were constructed to similar principles as the earlier batches, working out of London Marylebone on the Chiltern Mainline, and on the Gospel Oak to Barking route for the newly formed London Overground, replacing the previous Class 150's.
However, London Midland ones were built to a different standard, instead incorporating an intermediate gangway allowing for through access during rush-hour to increase internal capacity. Operating around Birmingham, these different 172's garnered immediate acclaim for their vastly improved interiors, kicking out many of the dusty Class 150's that dated back to the 1980's.
Today the Class 170's have been kicked up and down the length and breadth of the network with the changing tides of franchises. Whilst Chiltern's Class 168's have remained on their original route, Class 170's have been redistributed heavily. Midland Mainline replaced their 170's in 2006 with Class 222's, transferring them to Central Trains. Southwest Trains saw off their small fleet of 170's in 2006, selling them to First Trans-Pennine Express to operate routes between Manchester, Leeds, York and Hull. These have since been transferred south to Chiltern to strengthen their fleet in 2015. In 2003, several Anglia Class 170's were leased to form the fleet of Hull Trains, which worked a high speed service between London King's Cross and Hull, but were replaced by Class 222's in 2005, these being transferred to Scotrail. Franchise reorganization in the Midlands saw Central Trains split into numerous franchises, with the Class 170's being taken under the wing of London Midland, working trains in and around the West Midlands, and Cross Country, working long-distance trains between Cardiff and Nottingham, as well as Birmingham and Stansted Airport. Scotrail units have remained largely the same, whilst the Class 171's and 172's continue to ply their trade on their original operations.
