Some catenary lighting that still exists on the A30 and A4 in West London consists of Phosco P415 twin-135W SOX lanterns, with five lanterns per span. These lanterns can also be fitted with 180W SOX lamps. Anybody who has picked up a 135/180W leak transformer will know how heavy these are, so imagine 10 per span, plus the weight of the lanterns themselves. No wonder the columns had to be so heavy duty. But times have changed, and the majority of councils and contractors fit new lanterns with electronic control gear, which is considerably lighter in weight. That would cause reduced stresses on column and lantern fixings, and columns wouldn't need to be so heavy duty. Furthermore, if a CosmoPolis catenary lantern were designed it could be a tiny lantern. Some of us have seen how tiny a WRTL 2Tone is, and they can handle 140W CosmoPolis lamps. Smaller size means reduced windage, and again, reduced structural issues.I think you've made a really good point. The M25 used to use lighter-weight catenary lanterns along some parts; these were effectively 'bricks' instead of the traditional CU Phosco P415. I wonder how heavy the SON catenary lanterns were on the M5? Even so, like you say newly designed catenary lanterns comparable in size to the WRTL 2Tone are an excellent idea and would mean thinner columns. However, I feel LED would offer the most potential. These could be distributed in single, spaced out catenary lanterns or many small units with smaller spacings spread out along the whole catenary system. The former would probably be best because it would mean less lantern maintenance in the same sense that less columns equates to less maintenance.
I think you've made an excellent argument to put forward in favour for the reinstatement of catenary lighting!
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Does anyone know of any recent catenary installations on the continent? Since countries such as The Netherlands are big users, I would have thought they were still installing catenary systems in the 2000s?