As of 29 December 2009 (its latest update), all newly installed automated gate systems are covered by the 'Machinery Directive' and should meet the stringent safety requirements laid out within. The law puts responsibility not only on the installer but also the owner of the gates ongoing (i.e. ensuring the gates are maintained accordingly to these standards).
For example, all gate systems should have safety features installed in them to prevent crushing (and this doesn't mean a set of photocells, as these may not pick up a person standing between the gates).
The gates are not allowed to exert an initial pressure of more that 400N for more than 0.75sec, dropping down to 150N for the next 5 secs, coming down to 25N after the 5 seconds has elapsed.
The majority of mains operated hydraulic ram systems will probably fail the required standard, (when fitted on their own) and will require more often than not, the fitting of safety strips which allow the gates to meet the above standards.
Gaps, shear points, crushing zones, trapping points (to name but a few) all need to be assessed and accommodated for during design & installation and suitable safety features added to ensure risks are minimised........
As with anything in life, if corners are cut or installations are compromised through the lack of competence, then accidents are going to occur, and given the number of well publicised fatalities this year you'd be mad to install these gates unless you know exactly what you're doing.
(Most of the text above stolen and abridged from here:
http://www.theiet.org/forums/forum/messageview.cfm?catid=205&threadid=36562 )
