Murphy Plant Ltd.’s depot in Hemel Hempstead command a huge array of Crawler Cranes, which are in demand on locations across the nation – including construction sites in “Clean Air Zones” such as London and HS2. Tier One Contractors frequently stipulate high emission standards on their sites, even where this is not mandated by local government.
There are however two challenges – one financial and one of a technical nature:
- Replacing Crawler Cranes that do not comply with “Stage 3b” emission criteria is not cost effective, because these high value machines have long depreciation periods of typically 10-15 years.
- Diesel Engines on Crawler Cranes spend most of their operating times idling whilst they are holding loads. As a result they rarely achieve the operating temperatures that are necessary to regenerate passive Diesel Particulate Filter (DPF) systems – in other words, filters clog up and choke the engine.
Johnson Matthey provide active DPF systems which feature an integrated Diesel Burner unit, which can heat the filter to temperatures above 600°C – the threshold needed to combust diesel soot in air. JM’s BU-DPF, along with other active and passive JM systems, is accredited with the Energy Savings Trust (EST), whose approval is necessary to certify compliance.
The cost of Johnson Matthey’s retrofit solutions is a fraction of the replacement cost of cranes and is therefore a viable alternative to disposing of non-compliant machinery.
BISAF Ltd., who are JM’s UK Agent, are systematically installing JM DPFs on Murphy Plant Ltd.’s Crawler Cranes and issue the Certificates that are needed to allow the machines to operate in “Clean Air Zones”.
“The JM systems operate smoothly and without hiccups. BISAF installed the first system 10 months ago and since then they have retrofitted 10 of our machines – with more in the pipeline. The guys are efficient and work around our fast moving schedule.”