Class 168 Clubman

The Class 168 Clubman were the first new diesel multiple units to be ordered after rail privatisation. They were built for the Chiltern routes providing much needed extra capacity and remain on these routes today, operated by Chiltern Railways [1]. The 168s are used on fast and semi-fast services out of London Marylebone and are capable of 160kph / 100mph [2].
168 109 at Chalfont & Latimer

Information
Number built: 67 (19 3 or 4-car sets)
Built: 1997-2006
Builder: Adtranz Derby later Bombardier Derby
Motor: MTU 6R183TD13H diesel per car
Power: 1, 688 hp (1, 260 kW) or 1, 266 hp (945 kW)
Formation: Driving Motor Standard Lavatory (DMSL)+Motor Standard Lavatory
(MSL)+Motor Standard (MS)+DMSL or DMSL+MS+DMSL or
DMSL+MS+MS+DMSL

The original five Class 168/0s are 4-car sets based on the Networker cab design (they were originally 3-car but were strengthened to four), the subsequent and later built 168/1s and 168/2s use the Turbostar cab design and are very similar to the Class 170. These two sub-classes are a mixture of three and four car sets.

 
The Class 168s are fitted with trip cock equipment as they share lines with London Underground stock on the Harrow-on-the-Hill to Amersham route. This equipment applies the brakes if a London Underground signal is passed at danger [3].

The Chiltern fleet has being strengthened with a new sub-class 168/3 formed by transferred Class 170s from Trans Pennine Express [4].
Chiltern 168 111 at Haddenham & Thame Parkway

168 003 at High Wycombe

168 325 passes through Lapworth

At Beaconsfield

168 113 at Hatton

[1] Colin J. Marsden, DMU and EMU Recognition (Ian Allan, 2013) p. 154
[2] Gavin Morrison, British Railway DMUs in Colour (Ian Allan, 2010) p. 45
[3] Colin J. Marsden (ed.), "Class 168 Clubman", Modern Locomotives Illustrated No. 216 December 2015-January 2016 (Second Generation DMUs Classes 165-185) p. 22
[4] "TPE goes for new loco-hauled trains for new franchise", Today's Railways UK No. 173 May 2016