Lester:
Regarding the L&A shafts:
The L&A that you see on your Titanic deck plans does mean “Light and Air” but as Dan pointed out the amount of light that they admitted was intentionally minimal.
These shafts were developed in the late 19th century to admit light and air to the interior parts of a ship; cabins, passageways and bathrooms not next to the hull and therefore deprived of a porthole.
The Olympic class was the last large British ship to have them and so they are really a vestige of an earlier practice. If you have access to the Mauretania’s Shipbuilder or Engineering, the shaft arrangement up as originally intended in the 1890’s will make more sense.
Typically, the funnel and engine casings are surrounded by an additional sleeve of steel, perhaps 18” deep, running around the central casing. At the top of house were a series of port holes in hinged flaps called a coach top. The interior of the L&A shaft was painted white and light simply bounced down the shaft. At the different deck levels were portholes which frequently opened to admit the light and air.
Exactly how much light these shafts delivered is debatable, but keep in mind that in the 1900’s the public’s expectations regarding illumination were MUCH lower — most ship’s light bulbs of the period (1890-1920 and later) were on the order of 40 — 60 watts.
These L&A shafts also had the advantage of helping to insulate cabins from the heat of the boiler casing, as well as giving a chance for ventilation in rough weather since ports would be closed but the coach top lights could be left at least ajar.
As I mentioned, the L&A shafts on Titanic were a vestige and the term “Light & Air” was retained on the plans as a matter of convention. The only shafts that really worked as light shafts were the L&A trunks behind the First Class Smoke Room stained glass panels on the turbine engine casing. Light was admitted from the Boat Deck above and bounced down the shafts to illuminate these panels. (If you will look at the Promenade Deck plans of the shipbuilder, this trunk way shows up as the horse-shoe shaped blank space around the “TUR ENG CAS”).
White Star should be congratulated on this since illumination from both outboard and inboard walls in the Smoke Room helped even out the lighting and reduce glare.
The other L&A Shafts in the area are mostly for assisting in the ventilation of the galleys.
Again, with reference to the Prom Deck in Shipbuilder, inboard of the spiral staircase are two unmarked L&A shafts.
The after one is to assist extracting warm air from the after end of the Reciprocating Engine Room.
The unmarked L&A shaft forward of that ventilates the after end of the main galley.
Just forward of the unmarked L&A Shaft is one that is marked, and that ventilates the range in the Restaurant Galley on Bridge Deck.
Forward of the Smoke Room Lavy is a free-standing L&A shaft that runs down the center of the main galley.
The remaining shaft is on the after face of the Reciprocating Engine Room casing and ventilates the forward part of the main galley
If you look at plans, be sure to look only at Promenade deck — the other decks are drawn defectively and these details have been omitted by the draftsman to help with lettering in tight spaces.
Regarding the Recip. Engine Casing and skylight:
Air was forced into the engine room and left through the casing and skylight like a chimney. There were catwalks running up to the boat deck to access equipment and valves on each deck level, as well as open and close the skylight flaps. There was access to the engine room hatch at the boat deck level thru the tank rooms on the port and starboard side.
Engine room hatches are very difficult to imagine Anybody needs a picture looking up into Mauretania’s hatch, me know and I will email it to you.
Bill Sauder
[email protected]
