… generates the best outcome. Aggreko’s John Anderson advises on how to ensure continuous emergency power, heating and cooling across the rail network

Ensuring a continuous power supply across the railway network 24/7 is fraught with difficulties. At the same time, assets across the rail network require heating or cooling to maintain functionality. With careful planning and risk assessment, emergency back-up power, heating and cooling can be provided economically and efficiently, to keep disruption to a minimum, says John Anderson, Aggreko’s national accounts manager for rail.

With a territory covering hundreds and even thousands of square miles, and assets ranging from train stations, regional operating centres and depots, to signalling and tunnels – through to points heating and telecommunications, there’s a huge and varied power and temperature control requirement and lots of scope for things to go wrong.

The emergency plan
So, where are the weak points? Where are the gaps in your existing back-up power generation provision? How do you minimise the time between a grid outage and generators powering up? What are the most critical assets for which cooling interruption is simply not an option?

These questions can all be answered by producing a dedicated and regularly updated contingency plan. But where should you start?

It’s important to undertake a comprehensive site survey across your entire estate, covering all rail assets. It would be economical to examine your power, heating and cooling needs all at the same time, particularly focusing on critical infrastructure such as data centres and telecommunications facilities.

Your comprehensive contingency plan should create an effective back-up strategy to prepare for the worst in the event of fire, flood, weather disruption, explosion, national grid failure, or any other possible emergency. It should cover all eventualities – from sharp temperature drops, to power outages or telecommunications failure – and contain sufficient operational detail to ensure that the plan can be speedily put into action should the worst happen.

Here are some common challenges that demand priority focus:

1. Maintaining power in remote locations
As the UK rail network covers many remote and inaccessible locations, it’s essential to have a plan in place to power and service these sites. One such example is the 3,000+ trackside masts that support the Global System for Mobile Communications-Railway (GSM-R). Many of these critical masts are in awkward locations, which can be a problem if there are power cuts, when maintenance or repair is required, or when they require upgrading.

In such situations a mobile power supply is needed quickly to avoid downtime and subsequent service delays or safety risks. When speed is important it’s easy to overlook the simplest considerations. For example, it is essential to map out the access routes to site, taking into consideration soft ground, rough terrain, locked gates, or any other hurdle that might make access difficult. You may require use of specialist transport vehicles and portable trailer-mounted generators that can be easily moved. The challenge of how to refuel these generators also needs to be considered. Long lengths of cable may also be required to ensure masts are connected safely to the power supply.

In these unmanned areas, security of generator equipment might also be an issue. Secure containerised generators are available that are disguised to resemble generic construction containers – offering protection from theft and vandalism for the generator, fuel tank and distribution equipment.

2. Ensuring critical power
A zero risk approach is required for critical facilities, such as operations centres and data suites, which control and store vital information for effective railway operation. It’s therefore essential to produce a back-up plan that offers an extra layer of protection to existing back-up power, HVAC and refrigeration equipment. A detailed contingency plan should identify priority equipment and an appropriate rental equipment partner to survey your sites and provide a logistics and connection plan in advance, so that no time is lost in the event of an emergency.

It’s also important to regularly perform strenuous load testing of power, chiller and air conditioning systems. Using load banks to simulate power and heat loads under a variety of conditions will ensure that on-site systems and back-up equipment are robust and performing at optimum capacity.

3. Points heating
If the points heating on railway track fails during a cold snap due to a grid outage, or is out of action due to maintenance, generators are a quick and simple solution. They supply power to the trackside control cabins that feed through to the points heating elements. To make the solution more cost-effective, the generators can be connected to a thermostat, so they auto-start when the temperature drops below zero. The generator will stop again when the temperature rises; this provides fuel efficiency and keeps running costs to a minimum.

4. Specialist voltage ranges
The rail network works across a range of voltages, so it’s essential to plan ahead for specialist generator requirements. For example, train care depots run on high voltage power, while signal boxes and signalling systems demand 650V.

High voltage applications require additional planning due to the complexity of the set-up; so make sure this time is factored into your plan to avoid delays. Make sure your rental power specialist has a local depot holding your specified equipment and that you have priority rights to that equipment to minimise delays. In addition, it is important to have negotiated contractual prices for emergency equipment and understand your supplier’s response times to each site, to prevent surprises.

5. Keep going – off-grid
Large-scale rail infrastructure and building construction projects often call for new or upgraded utility supplies to meet increased energy demand. Achieving a new grid connection is complex, takes time and can be subject to unexpected delays. As such, it’s vital to be prepared and have an off-grid power strategy ready – using diesel or gas generators. This is essential during construction and the early operational stages of new assets.

In devising an off-grid energy strategy, consider whether it’s business critical to have a totally secure and stable power supply. If so, you will need to specify additional Uninterrupted Power Supply (UPS) systems.

Make sure that your off-grid power provider provides round-the-clock, real-time monitoring of the installed generators to ensure uninterruptible power and provide diagnosis and correction of any issues in real time. This is particularly important for assets located in remote locations. Remote monitoring can be used to inform a proactive service and maintenance strategy – ensuring continuity of supply and optimum equipment efficiency.

6. Keeping critical assets cool
In summer warmer weather can overburden HVAC and refrigeration plant. This can make it difficult to maintain required temperatures and kW cooling capacity. As a result, systems can struggle and become more prone to breakdowns. For sites such as signalling centres and data centres that demand cooling, this could cause serious disruption. Cooling may also be required for some fixed assets, particularly smaller signalling boxes and telecoms buildings, which are prone to overheating in summer.

Rental cooling equipment can support with supplementary cooling during periods of higher ambient temperatures. It can also act as the main cooling provider when a site’s plant needs maintenance or repair.

Planning for these scenarios in advance allows time to consider the most suitable hire equipment and ensure ease of installation.

Download Aggreko’s ‘Contingency Planning for Power Failure in the Rail Sector guide from: http://content.aggreko.co.uk/rail-disaster-recovery-plan

Aggreko’s UK rail division is RISQS accredited and provides 24/7 nationwide service and mobile power and temperature control technologies from 18 locations throughout the UK and Ireland