"Dynamic Track Stabilisation and high-speed handbacks
Dynamic Track Stabilisation (DTS) units are available on some of the more advanced tampers of the type you can see on this page, as well as
High Output tampers.
When a tamper is used alone to place the track in its design position and consolidate the ballast after renewal work, there is traditionally a line speed restriction of around 50mph for a period of time afterwards to allow the ballast to settle.
When DTS machines are used together with a tamper, their impact is to consolidate the ballast by simulating the equivalent of up to a week’s worth of trains, so the track won’t settle further. The result is that trains can run on the track at high speeds (80-125mph) straight after renewal work. This is called a
high-speed handback."