Under cold outside conditions, parked trains are heated and lighted partly or completely overnight for several reasons:

• in order to guarantee optimum comfort when service starts next morning.
• in order to ensure a comfortable working environment for cleaning personnel during the night
• in order to avoid damage to equipment due to freezing

In countries of Central and Northern Europe, overnight standstill consumes considerable amounts of energy.

Existing solutions to reduce this energy consumption include:

• Manual control: Comfort functions are manually switched off after service and back on to “preheat” the coaches 1 or 2 hours before service starts. This is however expensive and difficult to organise.
• Automatic control: Comfort functions during standstill are controlled automatically by an on-board timer or (in a more advanced version) by telematics (remote control).
• Reduction of conversion losses: A special solution to this problem has been developed at DSB: A software tool allowing for the common energy supply of two trains via one pantograph. For details, see Coupling of parked trains for common energy supply
• Gradual heating during service: Some experts propose unconventional measures to save overnight heating. On those lines not requiring the full train capacity on the first track section (i.e. between the first two or three stations), it could be sufficient to heat only one coach overnight, and heat the other ones by recovered braking energy on the first track sections. This would however require not opening some coaches to passengers before the second or third station. Such an approach is expected to find no acceptance in railways and is therefore not promising.

This evaluation focuses on automatic control systems.

Technical details

No general system specifications for an automatic control of overnight operation of comfort functions in trains can be given since on-board control of comfort functions is highly heterogeneous. Existing solutions mainly differ with respect to the following features:

• Centralised control device for the entire train
• Possibility to operate lighting and heating at one third or half intensity
• Special programmes for anti-freezing or preheating operation

This heterogeneity of operation concepts makes any standard solution difficult.