Under frame skirts play a vital role in the fight to maintain safe rolling stock. With the ever-present threat of strikes from flying debris, these skirts protect the electrical services, batteries and ancillary equipment sited under the train and remain an important safety critical area.
The damage caused by constant day-to-day use and wear and tear, along with strict cleaning regimes means that these skirts have a typical in-service life of about 15 years and often shorter.
Manufacture of these replacement skirts needs to be undertaken by companies familiar with working with the typical manufacturing material of aluminium and Sheffield based Birley Manufacturing have been a specialist in this rail metal fabrication area for over a decade and are the UK’s largest supplier of under frame skirts.
The use of coded welders and discipline of accountability for safety throughout the shop floor is vital as this is a safety critical area – imagine one of these falling off or coming loose at high speed. However in the final analysis it is the assembly and safety inspection regime Birley have in place that is the final arbiter when it comes to performance on the network.
The design is a balance between weight and strength to ensure maximum protection for minimal additional weight. Aluminium is an obvious choice because of its strength to weight characteristics and its rust resistance.
The skirts themselves start life as a framework constructed from 'T' sections. Panels are riveted onto this latticework and vented side panels attached before a special protective primer is applied. Special transport jigs are then used to transport them to the rail depots where old units are removed and installation of the entire new unit including a final protective paint topcoat takes about two to two and a half days.
These unobserved units serve an important safety role on the network. The contribution Birley Manufacturing have made to the UK rail fleet is a quiet success story - there is not an HST fleet on the network that does not have some of our under frame skirts fitted and they have proved the test of time.
