I used to know a professional electrician who would repeat his college lecturer’s mantra: “Lamps glow, bulbs grow!”
Examining two random packs of lamps, one of GU10 l.e.d.s, the other a miniature tubular flourescent, both give the lumens as well electrical power and incandescent equivalent in W. Though in the tiny print that satisfies regulations, more important than informing customers. Perhaps the manufacturers think most householders are comfortable with Watts, since we buy thousands of those at a time, but are totally in the dark about lumens, lux or indeed the SI basic unit of light intensity, the candela.
They may be right of course!
Wikipedia tells me …
The candela […] is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540×1012 Hz,[a] Kcd, to be 683 when expressed in the unit lm W−1, which is equal to cd sr W−1, or cd sr kg−1 m−2 s3, where the kilogram, metre and second are defined in terms of h, c and ΔνCs.[10]
So we’ve no excuse.
It goes on to say 1 candela corresponds to one average wax candle (!) and the wavelength is a green light near the human eye’s maximum sensitivity. So like the 0 decibel re 20µPa base for airborne sound pressure… despite all the high-flown Hard Sums and bramble-thicket arguments by anonymous committee types paid to stay out of labs and drawing-offices, the unit is anthropocentric !
‘Bout as bright as chapel altar candle, then.
Years back one could buy household DIY compendia of advice on simple repairs and the like. Are they still published?
Even “our” magazine, in its & Electrician rather than & Workshop era, sometimes got in on the act: workshop wiring and in one edition, re-seating the scullery tap using the lathe and improvised Keats Angle-plate.
;;;
Nicholas –
I never had to work at heights – just as well as they and I agree to differ, although my work sometimes meant short instances of remembering at least I was being paid to be frightened. I was though trained in using lifting-tackle and operating overhead cranes, which comes in good stead in my home workshop.
However, with some decades of caving, I am well aware of roped access technicques, and the industrial version was indeed started by cavers who spotted the wage-earning potential.
Among these, used industrially as well as for fun, developed the principle that your protect yourself from falling more than about an arm’s-length from the belay.
We do not use fall-arrest harnesses because that risks dangling helplessly in space over a dirty great drop and a long way from the nearest wall. Potentially as disabling or fatal as falling to the floor.
Instead we attach ourselves to belayed ropes by two short lines called “Cows’-tails”, an idea adapted from rock-climbing. Of different lengths for particular moves, the longer is still short enough for you to operate the karabiner on its end. Plus as far as possible, we avoid climbing above the belay-points, to limit any possible fall to cow’s-tail length or less.
(This is different from rock-climbing in which the leader trails the rope behind, so a fall is far as the last belay then the same depth again.)
The industrial version’s regulations demand twin ropes, adding to the complexity. It might reflect the greater risk of abrading the rope on some projection, on a high building.
Suspension-trauma, as you describe, is a serious matter; hence my concern about the man using the crane gangway as an access-platform. It is possible to ward it off by gently moving your legs – if you are conscious. I do not know what risk-assessment the two glaziers or their managers would have had to write, so I don’t know if all this was covered.
The slinger working on the the shipping-container should have been able to work from a ladder, but he did have to go on the top at times, probably when the hooks were lying there out of reach.
Mobile lifting platforms are de-facto people lifts and movers, even if only to reach the work point itself; though not for scaffolding accces and such-like. Some are terrifyingly high though, as I see in the yard of a tower-rental company next to the camp-site I use when at “The Fosse”. The operators have to raise and lower them fully, presumably in maintainance and testing the machines prior to customers’ use. They are clipped on.