identification | gas
The classification of gas street lighting lanterns follows the method used by
W. J. G. Davey, B.Sc. and A. R. McGibbon, A.M.I.E.E in their
paper Modern Gas Street Lighting Lanterns.
gas | square lamps
Square lamps, also known as Windsor lamps, were in general use for residential streets
and for some arterial roads, being suitable for classes H, G and F of the British Standard Specification BS 307.
The lamps may house cluster or alignment burners, and are generally fitted with some form of directional reflector.
The reflective devices themselves form a means of classifying such lamps.
gas | globe type lamps
Glove type lamps, either suspended or mounted upright on U-fixings, are more generally known, perhaps by the
manufacturers' trade names, e.g. the Rochester (Sugg) and Stechford lamps.
Incorporating up to fifteen mantles, they form an imposing an efficient gas street lighting unit, and are universally
employed for Classes G to D of the British Standard Specification 307.
(Note that lanterns such as the Supervia were available in both low and high pressure versions.)
gas | lamps with special mantles
These are all used on high-pressure gas mains. "The term "high pressure" is a comparative term only. With the introduction of
the incandescence mantle nearly half a century ago gas pressure became at once a
matter of great importance. At first 1½" of water column pressure was a
suitable pressure forthe Welsbach light, but it soon became evident
that better results could be obtained with higher pressures. Conditions changed when
the inverted burner and mantle were introducted - 3" of water column pressure was
desired. The important stage in the development of high pressure (or "intensified")
gas lighting was when the gas pressure was raised to about 8" of water column pressure
by mechanical contrivances - the earliest being water-driven pumps - to increase the
velocity, and therefore the knetic energy, of the stream of gas issuing from the gas
nipple orifice into the mixing tube of the burner. The energy of the higher pressure
gas jet entrained a greater volume of air than was possible with the lower gas pressure
and "this resulted in a hotter flame and a greater intensity in the incandescence of
the gas mantle." - Street Lighting By Gas With Special References To The High Pressure system, Dean Chandler, M.Inst. Gas E, APLE Conference Folkestone 1937.
gas | special directive fittings
gas | high-intensity low-pressure