available for navigational purposes.
The position of buoys in the North Sea has been determined by the
time required by sound to reach special receiving apparatus at fixed
points on the coast. This method was introduced soon after the
Armistice in Nov. 1918, but its application is limited to distances of
loo or at most 200 miles.
Accurate Determinations of Time and Longitude. The precision
of time observations has been greatly increased by the use of the
self-registering micrometer in observing transits. With this microm-
eter the personality of different observers is reduced to o!oi to O?O2,
so that the exchange of observers for longitude determinations is
only necessary in work of the very highest accuracy. The sending
and receiving of rhythmic wireless time signals has reached such a
degree of accuracy that the clocks at distant stations can be com-
pared toofoi or less. It should therefore be a simple matter to>
make accurate longitude determinations. The value of the new
methods was fully established in the determination of the difference
of longitude between Paris and Washington in 19134, when the
result obtained was 5 h l7 m 36!653 ^003.
Standard Time. The use of a system of zones of standard time
has been considerably extended.
Greenwich time is now (1921) adopted in the British Isles, Spain,
Portugal, Belgium, France and the Faroe Islands. Mid-European
time (i h. fast on Greenwich) is used in Germany, Denmark, Italy, .
Switzerland, Norway, Sweden, Austria and the western parts of the
Balkan peninsula ; and E. European time (2 h. fast on Greenwich) in
the eastern parts of the Balkan peninsula, including Greece. Time in-
Iceland is I h. slow on Greenwich. Russia still adheres to Pulkovo
(Pulkowa) time, 2 h. I min. fast on Greenwich. Divisions of lesa
TINAYRE TIRE
727
than an hour are used in several British colonies. Standard time in
the E. African Protectorate is 2 h. 30 min., in India 5 h. 30 min., in
Inclo-China 6 h. 30 min., in S. Australia 9 h. 30 min., in New Zealand
II h. 30 min. fast; in British Guiana 3 h. 45 min., the Sandwich Is. 10
h. 30 min., Samoa n h. 30 min. slow. In all other countries adopting
standard time the most suitable whole hour is employed. The
standard zones in Brazil are from 2 to 5 h. slow on Greenwich.
Uruguay, the Argentine Republic and Siam adopted standard time
in 1920.
In the United States in 1918 to the four zones already established
(1883) was added a fifth for Alaska alone. Standard time for this
zone is based on 150 W. longitude. Standard time in the four other
zones is based, as from the beginning, on the 75th, goth, tosth, and
I2oth meridians. The marking of the limits of the various zones lies
with the Interstate Commerce Commission, and they may be
changed at its discretion. The first four zones differ from each other
I h. in standard time; the fifth differs from the fourth by 2 hours.
The first zone is 5 h. slow on Greenwich.
Until recently no definite time system was employed at sea, each
ship adopting the local time corresponding to its position at a
certain instant, usually noon. In 1919 a system of hour zones similar
to that used on land, previously adopted in the French and Italian
navies, came into official use in the British navy, a change which will
greatly facilitate the interpretation of entries in ships' logs. The
" zone description " of each zone is denoted by a positive or negative
number equal to the number of hours slow or fast on Greenwich.
The central zone or Zone O lies between long. 75 E. and long.
7jW. : the zones to E. of this are numbered I, 2 . . .12,
and those to W. +1, +2. . . + 12. Zone 12 is divided cen-
trally by the iSoth meridian (the date line) and the + or prefixes
are used in its two halves. Near land the boundaries between the
zones are modified so as to agree with the time used ashore.
Civil and Astronomical Times. The civil day reckoned from mean
midnight, instead of the astronomical day reckoned from mean noon,
is to be adopted in the Nautical Almanac in 1925, and a similar
change has been decided on for the Connaissance de Temps and the
American Ephemeris. The same course will probably be followed by
astronomers, but some confusion may arise if the old expression
" Greenwich Mean Time " is employed in a new sense.
TINAYRE, [MARGUERITE SUZANNE] MARCELLE (1872-
), French novelist, was born at Tulle, Correze, in 1872.
She was educated at Bordeaux and Paris, and in 1889 married
the painter Julien Tinayre. Her earliest novel was Avani V
Amour (1897); but the one by which she is best known is La
Maison du Peche (1902). Her later works include La Rebelle
(1905); La Consolatrice (1907); Madeleine au Miroir (1912);
L'Ornbre de I' Amour (1910); La Douceur de Vivre (1911); and
Le Depart; Adut, 1914 (1915). She also published in 1910 a book
of travels, Notes d'une Voyageuse en Turquie.
TIRE (see 26.10x36). The modern motor vehicle (see MOTOR
VEHICLES) would not be possible without some cushioning or
shock-absorbing medium at the periphery of its wheels. India
rubber, properly fashioned and fabricated with metals and fab-
rics into tires, plays an essential part in providing this necessary
cushion. Structurally, tires are divided into two main classes :
solid rubber and pneumatic. The cushioning properties of solid
SW
FIG. i.
tires are due to the elasticity of the rubber and the design of the
tread, while in the pneumatic type compressed air is the cushion-
ing medium; the rubber tire in this case serving as a flexible,
yielding container for the compressed air. In both classes the
various types are made in a progression of sizes, varying in out-
side diameter to give the proper road clearance, and in width
to accommodate properly the weight the tires have to support.
History from 1910 to 1911. This period opened with the
motor vehicle industry served by clincher or beaded edge pneu-
matic tires (fig. i) of square woven fabric not larger than 55 in.
in section, suitable for use on passenger cars only, and giving
3,000 to 4,000 m. service. The trend of tire development had only
recently settled on this clincher type as the most logical of the
many inventions, and the shortcomings of the product were
varied and numerous. Americans, following British design,
were especially unfortunate in having a great deal of premature
failure due to " rim cutting." This clincher type was also difficult
to apply to the rims in the larger sizes, and troublesome security
bolts were necessary to keep the tire from creeping around the
rim. Progress in tire development has been influenced by three
considerations: first, the method of attachment to the rim;
second, increase in the durability of the tire; and third, the
development of new types of tires for new fields of usefulness.
The principle of the Dunlop-Welch wired-on bicycle tire had
been tried experimentally in motor vehicle tires by using a bulky
inextensible wire bead fastened to the wheel rim with " straight-
side " bolted-on flanges. This straight-side tire idea first became
practical for motor vehicle use in 1907 when an American manu-
facturer offered to the American public in perfected form his
''SSR
" detachable " straight-side rim and tire. Its progress was slow
because of competitive hindrances, but by 1910 the detachable
rim had become so much appreciated that the clincher tire
manufacturers were obliged to furnish some sort of a detachable
tire. The result was the " quick-detachable " (Q.D. clincher),
a tire fitting a detachable clincher rim and having its beads
shaped like the regular soft bead clincher but with an inexten-
sible wire bead core like the straight-side tire. During this
period of development the Q.D. clincher served admirably as
a transition type.
The merits of the straight-side (fig. 2), however, gradually
made it more popular than the Q.D. clincher, with the result that
the last Q.D. clincher rims were made in 1916. In the meantime
the European demand continued to be for the clincher type
exclusively, while except in the Ford sizes, they were discontinued
in American production. American army vehicles and motor
vehicles exported on straight-side tires have recently opened a
market for straight-side in other countries. The year 1921 found
the situation as follows: bicycles were fitted with single tube
tires in America and wired-on tires in Europe.
728
TIRE
Motorcycles were fitted with clincher tires both in America and
Europe, and aeroplanes with either clinchers (fig. 3) or wired-on
according to the demand. Passenger cars were fitted with Euro-
pean Standard clincher tires for European productions. Amer-
FIG. 3.
ican small cars took 3i-5n. American Standard clincher tires,
while cars using larger than 3^-in. took American Standard
straight-side tires. All American " motor trucks " using pneu-
matics operated on straight-side tires, and for solid tire equip-
ment took pressed-on, channel base tires (fig. 4).
BB
FIG. 4.
European " lorries " were fitted with the typical English band
tire (fig. 5). Progress in details of design, materials, and methods
of manufacture was very gradual, the general idea being always
to build a " balanced " tire, that is, one in which all parts were .
equally durable. There are practically no formulae or theories on
tire design (except the rubber compound formulae) of value to
T -
FIG. 5.
the tire manufacturer; whatever good qualities any particular
make of tire embodies are the result of persistent and constant
experimentation, combined with the policy of the individual
company controlling the standard of quality which it desires to
offer to the public. The square woven tires of 1920 averaged
5,000 to 6,000 m. of service. There was one outstanding develop-
ment during the period 1910-20, namely, the "cord construc-
tion." The cord idea was old, having been used in bicycle tires
in the 'nineties, but the " square woven tire duck " appeared to
be more practical for motor vehicle tires.
About .1912 electric automobiles in America created a demand
for " power saver " tires to which the tire makers responded by
offering special casings of cord fabric structure for which excep-
tional resiliency and lack of internal friction were claimed. Not
at all durable at first, as they were gradually perfected the
leaders of the industry became convinced that this was to be the
quality tire of the future (fig. 6).
BF
w ;
FIG. 6.
Ply separation and fabric breaks in cord tires are effectively
prevented because the cords, being completely insulated from
each other, provide a flexibility of the " carcass " without chafing,
TIRE
729
that greatly reduces injury from under-inflation and overloading.
Development in the two-ply " cable " cord construction and the
" multi-ply " construction paralleled each other. In 1920 the
merits of the multi-ply construction had prevailed to such an
extent that the " cable " cord was no longer made. After the
World War European tire manufacturers began to duplicate
American multi-ply cord construction in their millimeter beaded
edge sizes. The cord tires of 1920 averaged 7,000 to 8,000 m.
of service. Durability was also materially improved by increasing
the cross-section size of the tires. In 1920 practically all American
straight-side cord tires were made 10% over the nominal size.
Also the tire manufactures gradually succeeded by persistent
educational work, in getting car manufacturers to fit tires ade-
quate for the loads to be carried. During this decade a new use
was developed for pneumatic tires, namely their application to
motor trucks up to 35 tons capacity. The movement made very
little progress from 1910 to 1915. "Dual" (or twin), square-
woven fabric tires in passenger car sizes were first tried. Then
square- woven fabric tires of 8-in. and g-in. sections were employed
with results encouraging enough to justify putting a limited
number on the market. By 1916 automobile cord tire construc-
tion had been mastered sufficiently for trial in the truck sizes.
Success with 6-in., y-in. and 8-in. sections immediately demon-
strated the superiority of the cord construction and was followed
by regular demand from the public. The g-in. and lo-in. sections
were used to some extent but their future was in 1921 uncertain.
The typical solid tire of 1910 was the British " pressed-on "
band tire then in use in Europe and soon to be duplicated in
America. These tires were fitted to the wheels by simply forcing
or pressing on with a special press, but in the absence of con-
veniently located tire presses, some American manufacturers
adapted the metal base idea to a " bolted-on " design (called
" Demountable "), having bevels on the inside edges of the steel
band so arranged that hoop-shaped " wedges " could be fitted
to mount the tire, the whole assembly being bolted in place with
" side flanges." Early metal base tires in America failed pre-
maturely from fracture of the exposed hard rubber at the edge
of the base band due to rough streets. To remedy this the band
was made in " channel " form and the hard rubber protected
by the side of the channel. In 1913 as an experiment, a "channel
base " tire made to press directly on the S.A.E. (Society of
Automotive Engineers) standard wheel without traction plate
or staples, previously considered necessary, was tried. The
experiment was successful, and this new type was so much
simpler and less expensive that it rapidly superseded all other
types in America. In 1915 wide single solid tires were intro-
duced in America (8 in., 10 in., 12 in. and 14 in. wide) on the rear
of heavy trucks in place of dual or twin tires. In 1920 wide
singles and duals were almost equal in popularity.
The growth of pneumatic tire production in the United States
is shown by the following figures, those for 1913, 1914, 1915,
1918 and 1919 being estimates:
1913 6,588,000 1917 . . 25,845,656
21,000,000
35,000,000
32,400,000
1914 . . . 8,983,000 1918
1915 . . . 12,840,000 1919
1916 . . . 18,564,957 1920
Structure, Materials and Manufacturing. Solid tire structure is
clearly shown in figs. 4 and 5. The tire maker's problem is to attach
the tread rubber, which must be of highest quality, to the wheel.
This necessitates a steel foundation band, a thin layer of hard rubber
specially compounded to adhere to the steel, to which the tread rub-
ber will also adhere. No practical way of making the tread rubber
adhere to the steel is known. The component parts of the straight-
side pneumatic tire are indicated in figs. 2 and 6. The bead portion
has imbedded in it a circular inextensible wire core, usually of many
strands in the form of braid, cables, or coils (to give a certain amount
of flexibility). This wire anchors the tire to the rim, prevents it from
blowing off, and gives rigidity enough so as to prevent the tire from
creeping on the rim when inflated. The body or " - " " ~ f * t -~
1 carcass " of the
pneumatic tire consists of bias " plies " of cotton fabric impregnated
with adhesive rubber " friction," insulated from each other by a
thin " skim coat " of the rubber, and having the edg^es of the plies
folded or " tied in " alternately over and round the wire bead core.
(See fig. 7 showing detail of a typical bead " tie-in.")
Since the function of the carcass is to serve as a strong yet
flexible container for the inner tube with its charge of compressed air,
the specifications covering the fabric call for great strength, uni-
formity of weight, freedom from grit, and particular grades of long
staple cotton (Arizona, Sea Island, Egyptian, Sacalarides, Pealer,
etc.). The two general classifications are: first, " square-woven "
fabric, weighing 17$ oz. per sq. yd., woven from warp and filling,
twisted of 1 1 strands of No. 23' yarn and having a tensile strength
TP
SSR
FIG. 7.
of 425 Ib. per in. of width (both warp and filling) for the best
fabric. The number of plies used are 3^-in. 4-ply, 4-in. 5-ply, 4j-in. 6-
ply, 5-in. 7-ply. Second, "Cord" ply-fabric, which is primarily a
warp composed of parallel cords of combed Arizona or Sea I.
cotton resembling fish line and weighs 14 oz. per sq. yard. The
parallel cords would get snarled up in the tire building processes, so
for handling purposes it is necessary to weave a single light filling
thread into the cord, 2j picks per inch. Each cord, (((23)s)3)
cabled yarn, has a tensile strength of 20 Ib. In cord tires the
cords of each ply must cross those adjacent, consequently the direc-
tion of the bias is reversed in the successive plies, which number
as follows: 3j-in. 4 plies, 4-in. 6 plies, 4-in. 6 or 8 plies, 5-in. 8
plies, 6-in. 8 or 10 plies, 7-in. 10 plies, 8-in. 12 plies, g-in. 14 plies, and
lo-in. 16 plies. As mentioned above, the tire plies are " tied in"
round the wire bead core. To make a bead proof against rim cutting,
etc., the most improved designs include narrow reinforcing strips
of frictioned fabric (see figs. I and 7). The outermost of these is
named the " chafing" strip. The outside of the carcass is entirely
covered with rubber; the sides with a " sidewall " layer, i^-in. thick,
and at the tread portion with " cushion stock," " breaker fabric,"
" undertread," and " tread." The tread is the thick, tough, firm,
wear-resisting face of the tire which is in contact with the road sur-
face. The forces and stresses of vehicle operation are so severe in
their tendency to tear the tread from the carcass that tire makers
have found it impracticable to attach the tread directly to the car-
cass, and have had to resort to the interposition of the soft elastic
adhesive " cushion " and open mesh " breaker fabric " to taper off
the severity of the shearing stresses that would loosen the tread.
Another very important function of the cushion and breaker is to
prevent fabric rupture of the carcass by softening and spreading
the intensity of impact of rough roads. The design and quality of
the tread rubber must be worked out to wear at least as long as any
other part of a balanced tire. The simplest smooth tread is a thin
crescent in cross section ; and in the case of non-skid designs they are
generally crescent cross section with geometrical depressions or
protuberances. The physical properties most desired are toughness,
to resist cutting and chipping, and attrition resistance to provide
against abrasion from road surface friction.
There are no particular differences of design for the inner tubes;
nearly all makes resemble each other very closely. Highest quality
rubber with little or no compounding except sulphur is used for
grey tubes. The best red tubes are compounded with antimony
sulphide. To be satisfactory the tube must hold air; not crack nor
check in storage; not stretch out of shape; not stick to the casing;
not split nor tear easily; not be affected by heating; and must be
repaired easily. " Flaps," made of inexpensive rubberized fabric,
are used in straight-side tires to prevent the tube from being pinched
or nipped under the edge of the bead, and to keep water and rim
rust away from the tube.
Only general ideas of manufacturing can be mentioned. First,
there is " stock preparation" ; the rubber and " compounds " are
mixed, the fabrics " frictioned " and " skimcoated " with rubber,
gauged to a very exact thickness, the frictioned fabrics cut to proper
widths on a machine called the " bias cutter," the cushion, under-
tread, and sidewall stocks are sheeted out and cut to width on the
calender, the tread rubber is prepared either on the calender or the
730
TIROL TIRPITZ
" tubing " machine, and the bead wires are padded with rubber and
frictioned fabric and cold pressed into shape. (See RUBBER for stock
preparation.) " Building " the tire is the next step. A " core " in
shape and size like the inside of a finished tire used as a building form,
is mounted on a stand which permits the core to revolve. The tire
plies are drawn taut around the core and rolled down smooth one
after another, and at the proper time the bead is put in position.
After the last ply is in place the tie-in at the bead is made; the
building is finished by adding the sidewall, cushion, breaker strip and
tread. During the decade 1910-20 tire building changed from all
hand work to a combination of hand and machine building. In
addition to saving labour, the machines turn out more perfect work.
The final step is the vulcanizing or " curing." Fundamentally this is
simply the processes of subjecting the " uncured " tire to a definite
degree of heat for a definite length of time while the tire is confined
under pressure in a strong iron " mould " (with an iron " curing
core " or inflated " air bag " inside the tire). The heat effects chem-
ical changes in the rubber compounds just as in cooking. Quality in a
tire is very dependent on the curing. Not only must there be an
optimum cure but the mould pressure must not disturb the fabric
lest " buckles " or " mould pinches " be formed. This last is so
important that many manufacturers resort to the more expensive
double cure process the carcass is semi-cured to " set " the rubbers
and fabrics with much less danger of fabric displacement, after which
the tread is cemented in place and the cure finished.
Tire Troubles. For the purpose of general analysis in pneumatic
tire service, five major tire troubles are recognized. They are: (i)
unsatisfactory tread wear; (2) separation either (a) between plies
of fabric or (6) of tread from carcass; (3) fabric ruptures; (4) bead
troubles; and (5) tube troubles. In each case it is possjble to
classify pretty completely the origins of the mischief. Of course,
many instances of premature tire failure are due to defects of design,
materials or manufacture; on the other hand, by far the more
frequent cause of tire trouble is abuse in the hands of the user as
outlined below:
Abrasion
Wheels out of alignment
Too much power
Improper use of brakes
Skidding
Abrasive road surfaces
Under-inflation
Sharp stones cutting tread
Deterioration from oil
Excessive flexing
Riding under-inflated
Riding car tracks
Overloading
Riding flat
Abuse of rough roads
Cuts
Heating from speeding
Water-soaked fabric
Overload
Over-inflation
Under-inflation
Stone bruises
Premature ply separation
Cuts
Exposed fabric water-soaked
Speeding on rough roads
( Bent rims
\ Under-inflation
Unsatisfactory
Tread Wear
Separation
(a) between plies
of fabric
(6) of tread
from carcass
Fabric
Ruptures
Bead
Troubles
caused by
caused by
caused by
caused by
Riding flat
Leaky valves
Puncture
Tube Troubles \ caused by Heating from speeding
Pinching under bead
Tears from rough handling
Neglect of spare tube
Solid tire troubles are confined to premature wear in the form of
cutting, chipping, and breaking large chunks out of the tread; dis-
integration in the heart of the tire due to the accumulation of the
heat of internal friction on long trips (rubber is such a poor conductor
that heat is not adequately dissipated by windage) ; and separation
of the whole mass of the tread rubber from the steel base-band. This
last is a defect in materials or manufacture except in cases where
external abuse fractures the hard rubber. In order to cushion a
specific load properly a tire must not have too high air pressure; on
the other hand, under-inflation results in excessive flexing which in
turn brings on premature ply separation and fabric breaks. Ex-
perience has demonstrated that a pneumatic tire should not flex more
than 11% (for large tires) to 15% (for small tires) of the section
diameter of the tire. Recommendations designed to advise vehicle
manufacturers and users as to the proper conditions under "which
the tires should be used are given in their "carrying capacity"
schedules, as indicated in the following table.
Carrying Capacities and Inflation Pressures of Pneumatic Tires
S.A.E. Standard. /
For passenger cars
For commercial
vehicles
Tire
Size
Fabric tires
Cord tires
Cord tires
Max'm
load
per tire
Ib.
Air
pressure
Ib. per
sq. in.
Max'm
load
per tire
Ib.
Air
pressure
Ib. per
sq. in.
Max'm
load
per tire
Ib.
Air
pressure
Ib. per
sq. in.
il
ti
1
9
10
375
570
815
1,100
1,500
45
55
65
75
85
400
600
850
1,200
1,700
40
5
60
70
80
850
1,200
1,700
2,200
3,000
4,000
5,000
6,000
"
70
75
80
90
100
IIO
I2O
130
(J. E. HA.)
TIROL (see 26.1010), an Austrian Territory, divided by the