Track laying using a moving line of machines
Plasser & Theurer gave the concept of track relaying using a moving line of machines a decisive impetus by the development of track relaying techniques. The designation UP 1, given by German Federal Railways to the first relaying train type SUZ 2000 built by Plasser & Theurer, records the historical position of this first relaying train to use the assembly-line method.
The second generation:
The additional relaying trains SUZ 500 J (US) in use on German Federal Railways from 1977 onwards, for efficient operation in short intervals between trains, introduced the next generation of relaying techniques. Instead of multi-part relaying trains, track renewal machines now appeared in which all the work steps were integrated. The material train was propelled by the track renewal machine.
The SUM series:
The sleeper pick-up and laying section and the ballast regulating chain are mounted on an articulated frame with three bogies. While working, the frame is raised by turning a spindle so that the middle bogie is free and all the work necessary for relaying can be carried out in this area. The rear bogie is already running on the newly laid track.
The SMD 80 series:
The special feature of the SMD series is the crawler tractor. The sleeper wagons and the front section of the relaying machine travel on the old track while the rear section of the relaying machine is supported on a crawler tractor. The crawler tractor runs in the gap between the old sleeper pick-up unit and new sleeper laying unit and provides a high tractive effort independent of the weather conditions.
Moreover, the SMD system provides a technology which, thanks to fast conversion without additional parts, can be used both for track renewal and track laying.
If required, the machines can be equipped with an old sleeper pick-up device, an electro-magnetic rail fastening collection unit, a crane to pick up pallets of new sleepers deposited next to the track, and a water sprinkling unit for reducing dust.
The SVM series:
The SVM 1000 high-speed laying machine was developed and built in 1981 exclusively for laying new track. This machine is operating successfully in Australia.
The SVM 1000 S represents a further development within the SVM series: a laying machine with integrated supply of new rails. Using this laying technique the new rails required are carried on suitable wagons and transported ahead of the laying unit using a rail conveying unit. This means there is no need to lay out the new rails ahead of the machine operation. The laying unit of the SVM 1000 S is loaded onto a wagon for transfer travel and can thus be transported quickly and easily.
You can find suitable specialist literature to the topic here:
The Basic Principles of Mechanised Track Maintenance
This book is dedicated to the many people involved in the day to day planning and performance of track maintenance activities. Providing a practical approach to everyday challenges in mechanised track maintenance, it is not just intended as a theoretical approach to the track system.
Railways aim at transporting people and freight safely, rapidly, regularly, comfortably and on time from one place to another. This book is directed to track infrastructure departments contributing to the above objective by ensuring the track infrastructure’s reliability, availability, maintainability and safety – denoted by the acronym RAMS. Regular, effective and affordable track maintenance enable RAMS to be achieved.