The 'E' Type was fitted with Triplex glass. The windscreen was laminated 'TripleX' and cost Jaguar ?8/7/4 whilst the side and rear screens used toughened glass. The headlamp cowls were also produced by Triplex. Early cars would have had plate glass windscreens (marked as such), later cars would have float glass windscreens but would only be marked as 'Laminated' or 'Toughened' glass. More data is required to know when this change took place.
Triplex of Kings Norton, Birmingham:
1912 - Public company incorporated. The need for the specialist production of safety glass led to the formation of the TripleX Safety Glass Company to operate in Britain certain French patents for laminated glass. The manufacturing process involved fixing Xylonite or some other transparent material between 2 sheets of glass, thus triplex glass
1919 - Triplex safety glass cowlings were added to provide weather protection for the cockpit in the Handley Page aircraft used on the London-Paris service
1922 - The company was taken over by a public company of similar name
1927 - Purchased a new factory at King's Norton, Birmingham with the support of a loan from Guest, Keen and Nettlefolds
1927 - Pilkington developed a process for making thin plate glass suitable for Triplex and became an important supplier to Triplex
1929 - Pilkington and the Triplex Safety Glass Co formed a joint company, called Triplex Imperial, to build a works at Eccleston, St. Helens, to produce laminated glass; the factory had Pilkington management with support from Triplex.
1929 - The company had holdings in Triplex (Northern) Ltd, the Triplex Safety Glass Co, of North America, and Triplex (Continental) Ltd[8]
1930 - Triplex glass was fitted as standard on Austin cars[9]
1932 - A process for large-scale toughening of glass was developed by St. Gobain in France; Pilkington obtained an exclusive licence for Britain. Pilkington and Triplex then entered into agreements for Triplex to manufacture toughened glass for sale only to the motor and aircraft industries. The Triplex companies paid a royalty of 10 per cent on sales until April 1936. Pilkington reserved the right to exploit toughened glass for other uses
1935 - Royalty payments on TripleX toughened glass came to an end
1936 - Reduced prices of safety glass to encourage car manufacturers to continue to fit their products in windows in the face of competition from others who fitted ordinary glass. 18 Manufacturers agreed to fit TripleX in 100 percent of uses. By the end of the 1930s the Triplex companies were producing about five times as much toughened glass as laminated glass
WWII - Manufactured parts for the De Havilland Mosquito and other aircraft, eyepieces for gas masks, etc. Made plastic components at Kings Norton and in one of the 2 factories at Willesden. The Eccleston factory was used for munitions.
1951 - Triplex developed "zoned" windscreens, giving a zone of relatively clear vision in case of breakage, following similar developments on the Continent. Also developed heated rear windows for cars.
1954-1957 - Sir Alastair Pilkington and Kenneth Bickerstaff of the UK's Pilkington Brothers developed the first successful commercial application for forming a continuous ribbon of glass using a molten tin bath on which the molten glass flows unhindered under the influence of gravity - float glass
1955 - Triplex acquired Pilkington's interest in Triplex (Northern) in return for shares in Triplex Safety Glass. Pilkington began purchasing Triplex's shares in the market.
1959 - Pilkington?s Queenborough factory on the Isle of Sheppey in Kent opened, the original glass products were made under various brand names like Triplex, Sigla, Bilglas or SIV
1960 - first significant sales of 'float' glass which would rapidly replace rolled 'plate' glass in automotive applications
1963 - Motor Show exhibitor. Glass.
1965 - Pilkington owned more than 50 per cent of Triplex which then became a subsidiary of Pilkington.
1972 - Pilkington acquired the remaining shares in 1960the company
2006 - bought by Nippon Sheet Glass Company
Today - Pilkington Classic are dedicated to producing low volume glass for classic cars, prototypes and concept cars. Output is typically 50 screens/day
Triplex Glass Date Codes
All Triplex glass of the period was date marked with a code embedded into the logo. Cars made in the 1950?s to the late 1970?s can be dated by the ?TRIPLEX CODE? etched into the toughened glass. Note that it dates the glass not the date the car was built. The year code can be found in the Nine letters that make the word TOUGHENED or LAMINATED. One dot below a letter gives the year of the decade:
T = 1 L = 1
O = 2 A = 2
U = 3 M = 3
G = 4 I = 4
H = 5 N = 5
E = 6 A = 6
N = 7 T = 7
E = 8 E = 8
D = 9 D = 9
No dot = 0 (or possibly a dot under a space after the last letter)
To determine the approximate month of production look for two dots in the TRIPLEX logo on the glass. One dot above T, R, E, or X gives the quarter of the year the glass was manufactured:
T = Jan, Feb, March,
R = April, May, June,
E = July Aug, Sept,
X = Oct, Nov, Dec.
Example: TRIPLEX TOUGHENED, with one dot over the ?R? in Triplex, and the other under the last ?E? in Toughened, indicates April/May/June 1968
A different coding system was applied for the post-war TRIPLEX laminated windscreens destined for the USA, whereby the year of manufacture was mentioned in two figures e.g L61V. The quarter coding system on basis of the word TRIPLEX was identical to the TOUGHENED and LAMINATED versions. After Jan 1969 the year indication is identical but the month code changed and now indicated by multiple dots over the word TRIPLEX:
Other codes
AS1 = American (National) Standard (AS-1 is required for all windscreens and at least AS-2 is required for sides and backs. AS-1 can only be made out of laminated safety glass while all other AS numbers can be either laminated or tempered, as long as they meet the minimum AS requirement)
AS-WS = American (National) Standard - Windshield. Seen on glass from the early 1950's and was superseded by AS-1
L61V = Laminated 1961 required for USA
M = The M number is a model number for the piece of glass, which identifies the type of construction. The M number is unique to the manufacturer, so an M number of M471 by one manufacturer could be different than glass labelled as M471 by another manufacturer. It identifies the glass construction, including the colour and thickness.
DOT 17 = the Department of Transportation (National Highway Traffic Safety Administration) who assign codes to the manufacturer of the glass and '17' is assigned to Triplex Safety Glass Company Ltd
BS857 1967 = British Standard specification for safety glass for land transport, published 30 June 1967 and still in force. A screen marked BS857-1 was produced after January 1973; BS857-2 was produced after the second amendment to the standard in September 1980. In addition either "Z", Z1", "Z2" or "WHP" on windscreens. All other windows either "L", "Laminated", "T", "CHT", "F", "Float", "P", "Plate", "S", "Sheet". ("T" = Heat treated, toughened glass, "CHT" = Chemically toughened safety glass)
Kite mark = originally conceived in 1903 as a symbol to identify products manufactured to meet British Standards' specifications. It came from the kite shape of the graphic device from an upper-case B (for British) on its back, over an S (for standard), enclosed by two lines
SUNDYM = Triplex trade name for tinted glass; note dots over certain letters suggesting a code
AGREE = Agree, French for certified (the dots above the EE are accents, not codes!)
TP.GS.6 = French certification code
XXX in circle - TripleX logo - some have a dot in the centre; meaning of absence or presence of dot unknown
PLATE = Plate glass, manufactured by rolling molten glass on a table ceased production for automotive glass in about 1960
FLOAT = The successor to plate glass, created by floating molten glass on a bed of molten tin in a continuous process. Became the industry standard from mid 1961
LAMINATED = Fabricated by sandwiching and bonding annealed glass (annealed glass has been processed to reduce residual stress - unlike tempered glass) on both sides of a tough transparent plastic core. Also seen as 'L'
TEMPERED = Tempered glass results not from a glass creation process, as does plate and float glass, but from a post-processing thermal treatment. In automotive use both plate glass and float glass are tempered to improve damage tolerance. Both tempered float glass and laminated glass remain in common use today. Plate glass is no longer produced for automotive use. Also seen as 'T'
The codes were sandblasted on using a stencil. Fired-on white ceramic paint, decals and baked on black enamel are not correct.
Example Logos
The first example came off car #885268, the second came from Pilkington Classic, the remainder are unknown vehicle origin
August 1968 car, screen replaced between 1973 and 1980:
Car #888330, March 1963:
Horizontal Triplex logo on headlamp glass of OBL car:
Car #875343 OBL:
Headlamp glass left hand:
Headlamp glass right hand:
Note how the Kite symbol is always pointing to the outer edge.
Headlamp glass from around 1969, logo vertical:
Side glass 1963 FHC:
XK120 Aero screen:
NOS headlamp glass dated 1964:
Headlamp glass:
Trivia
1. Not even Pilkington Classic know why the glass was date marked. It serves no useful purpose apparently and modern glass does not always have it.
2. Pilkington Classic will make new glass with one of their heritage logos with no date code. They can also do tinted, graded tint, heated and containing a radio aerial
Note: If you have a photo of your screen/side/rear glass logo please email or PM me with it as it would be good to create a library of the various styles. Not easy to photograph but putting a piece of black matt vinyl behind helps
