High Output

Our High Output team delivers rapid renewals

Passenger demand for train services has doubled in Britain over the last 20 years. More frequent services mean tracks need to be renewed more often. High Output (HO) keeps the railway running, carrying out 70 per cent of Britain’s track renewal work.

Less disruption

HO teams are on the railway every night, carrying out vital track renewals overnight that used to take entire weekends. This means less disruption to train services.

Each night, HO teams replace up to a mile (1.6km) of ballast, and renew rails and sleepers over ¾ of a mile (1.2km), on the plain-line (straight) track. The track is settled enough for train services to run at normal high speeds straight after HO work is finished. 

Find out about our high-speed handbacks at junctions

Our machines

The ballast cleaning system (BCS) and track renewal system (TRS) trains operate in a conveyor process, renewing the track as they move along it.

Both the BCS and TRS are supported by tamper/dynamic track stabiliser machines that accurately position the track and consolidate ballast after renewal.

How our High Output machines work

Our High Output Plant System (electrification on the Great Western Mainline)

Watch the video below to find out more.

The High Output team

Around 1,200 people work in HO on the tracks and in our York and Birmingham offices, seven operations bases – from Millerhill in Scotland to Taunton and Eastleigh in the south of England – and at our five delivery depots, in Newcastle, Doncaster, Crewe, Bletchley and Swindon. Half are subcontractors, who work with us to deliver our projects.

Our renewals are a collaborative effort from the planning stage to logistics and delivery – getting the machines to the right place at the right time, making sure they can work safely to capacity.

It’s a 24-hour cycle, from getting the systems ready in the operations bases, to preparing the track by removing lineside equipment (and putting it back afterwards), starting up the machines and bringing back the old materials. A typical night sees possession of the track at 22:30, then handback at 06:00, with the system working 00:30 to 02:00.

Innovations lead to continuous improvement. For example, we’ve developed improved laser control at the cutter bar on the BCS, and make use of on-train surveying.

At a glance

  • 7 Network Rail owned machines: 5 BCS and 2 TRS
  • £300m invested by Network Rail  in HO in the last 12 years
  • Third largest HO fleet in the world
  • Teams working every night, 12 months a year
  • 50-60 people on a track relaying site during renewals
  • 600 people working on Saturday nights at peak times
  • Typically ¼ mile track replaced in 7.5 hours
  • Track handed back at up to 125mph after renewals
  • ½ mile BCS – longest train on the network
  • 800 tonnes of new ballast carried on BCS every night
  • HO renewals forecast to amount to 2,000km of ballast renewal and 700km of rail and sleeper renewal in 2014-2019
  • 5 shifts for each BCS every week

Find out more