50255 Heating and air conditioning on Class 165 and 166 units

February 2012 in Train Operations

Rolling stock Work environment South West

A reporter raises concerns about the effectiveness of the heating and air conditioning systems on the Class 165 and 166 units used by First Great Western along the Cotswold Line.  In the recent hot weather, there have been instances of passengers and staff feeling faint and overheated whilst travelling.

The Class 165 units do not have any air conditioning units installed so air only passes through the carriages when windows are opened.  Class 166 stock has heating/cooling systems onboard but they are felt to be ineffective in very cold and very warm weather, especially in the middle carriage. There are ways to isolate the system but this is not something that the reporter feels they are able or allowed to do. 

The reporter is concerned that the lack of cool air during the warm weather could mean that passengers and staff suffer from heat exhaustion.  To get some respite, Guards are able to go into the back cab and turn the air conditioning up.  However, Customer Hosts who carry out the trolley service for passengers are unable to do this.

Additionally, the trolley service is only provided from Monday to Saturday.  With no service on Sundays there is the concern that passengers could be travelling long distances without water, such as on the four hour journey from Paddington to Hereford.

It appears as though the air conditioning is actually blowing out hot air in hot weather.  If this is occurring, one suggestion is for the air conditioning to be switched off and the windows, currently locked out of use, to be opened on the Class 166 units. 

The reporter would like the problem to be investigated and some modifications made to the system. 

Could First Great Western:

• Consider carrying out tests to determine the effectiveness of the air conditioning on board the Class 166 units?
• Carry out any necessary modifications to Class 166 stock to prevent the overheating    experienced by passengers and train crew?
• Outline the available options to improve the situation on board the Class 165s

Response from First Great Western

As the reporter correctly states, 166X Class units are fitted with a combined Heating, Ventilation and Air Conditioning (HVAC) package which has, for some years, suffered from declining reliability and maintenance issues. These issues have been added to by certain components no longer being manufactured.

Whilst various long term options to provide a tolerable carriage environment have been explored, we have recently adopted a policy of isolating the hot water supply to the heating in the summer period. This is because the complex automated system could not be relied upon to regulate the vehicle temperature. The downside of this policy is that vehicles can be chilly during the early morning and late evening in the colder summer months.  The heating is reinstated in the autumn but unseasonably warm weather will still result in uncomfortably warm carriage temperatures.

The cooling function is the real Achilles heel of the original equipment fitted to the fleet and is now considered all but un-maintainable due to the component rarity and compatibility issues with environmentally compliant refrigerant gases.

The entirely unsatisfactory situation described above has resulted in the development of a joint initiative between First Great Western and the rolling stock leasing company, to explore alternative HVAC systems that would be compatible with the 166x fleet.  This would result in much greater reliability and compliance with current environmental legislation.

A system developed by Wabtech Engineering has been chosen and its relative simplicity should improve reliability.

The project is well underway with 6 of the 21 strong fleet fully fitted and producing encouraging performance data. The current fitment plan aims for the complete fleet to be modified by end of February 2012, in plenty of time for the summer season.

The 165X fleet is more suburban in nature and is only fitted with carriage heating. No cooling provision has ever been fitted and is unlikely to be considered before the end of the current FGW franchise.  The heating system on the 165X fleet is generally considered to be quite effective with no significant reliability issues.