GB2129158A - Optical fibre cable - Google Patents

Optical fibre cable Download PDF

Info

Publication number
GB2129158A
GB2129158A GB08328212A GB8328212A GB2129158A GB 2129158 A GB2129158 A GB 2129158A GB 08328212 A GB08328212 A GB 08328212A GB 8328212 A GB8328212 A GB 8328212A GB 2129158 A GB2129158 A GB 2129158A
Authority
GB
United Kingdom
Prior art keywords
optical fibre
fibre cable
sheathing
accordance
cable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08328212A
Other versions
GB8328212D0 (en
Inventor
Charles Robert Hand
John Carswell Smith
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Standard Electric Corp filed Critical International Standard Electric Corp
Publication of GB8328212D0 publication Critical patent/GB8328212D0/en
Publication of GB2129158A publication Critical patent/GB2129158A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4401Optical cables
    • G02B6/4429Means specially adapted for strengthening or protecting the cables
    • G02B6/4436Heat resistant

Abstract

An optical fibre cable resistant to a nuclear blast comprises a conventional optical cable (10) surrounded by a heat insulating material (e.g. fibreglass, PTFE etc.) (12) and a sacrificial, flame-retardant outer jacket (14) (e.g. polyurethane). <IMAGE>

Description

SPECIFICATION Optical fibre cable This invention relates to optical fibre cable and, more particularly, to such cable that is able to function after exposure to intense light and heat radiation such as might be experienced in a nuclear explosion.
The use of light signals and optical fibres is to a considerable extent displacing the use of electric current and standard metal conductors for the transmission of data and communication signals.
The use of optical fibres requires that they be incorporated in cables in such a way that they are protected from environmental and other usage conditions. Thus, various cable constructions have been devised that protect the fibre from normal environmental and use conditions in a generally satisfactory manner.
With the increased usage of optical fibre cable by the military, a requirement has been specified that the cable must be able to survive and operate after a nuclear event, for example, a nuclear bomb explosion. Thus, the cable must be sufficiently rugged ta withstand normal environmental and use conditions and must additionally be constructed to withstand the intense light, high winds and high temperature developed during and after a nuclear blast. That is, after the blast, the optical fibre must be capable of transmitting light and the cable must be sufficiently intact to withstand the forces imposed by debris scattered about by an explosion as well as the other normal environmental and use conditions.
Accordingly, it is an object of this invention to provide an optical fibre cable particularly suited to survive a nuclear event and to protect the optical fibre in such a way that it is not broken or melted during the event.
According to one aspect of the invention there is provided an optical fibre cable comprising a sheathing, optical fibres contained within the sheathing and a heat-insulating material surrounding the sheathing.
According to another aspect of the invention there is provided an optical fibre cable comprising a sheathing, optical fibres contained within the sheathing panda heat-insulating material surrounding the sheathing and a heat-insulating material is in turn surrounded by a sacrificial jacket which is flame-retardent. In this way the initial light pulse generated during the explosion will char or vapourise the sacrifical jacket without unduly damaging the heat-insulating material or the cable surrounded by it.
An embodiment of the invention will now be described by way of example with reference to the accompanying drawing in the form of a crosssection through a cable constructed in accordance with the invention.
The drawing illustrates a generally conventional cable 10 surrounded by a heat insulating material 12 and a sacrificial, fiame retardent jacket 14. The generally conventional cable may be of any suitable type and in the embodiment disclosed here includes a pair of longitudinal strength members 16, 1 6 located on diametrically opposite sides of the cable axis. These strength members 16, 16 can be any of a variety of materials to provide tensile strength to the cable and in this embodiment are cords of aramid fibre of 7100 Denier (a measure of weight per unit length, typically given in grams per 9,000 meters). An example of a suitable aramid fibre usable with this invention is that sold by E. I. Dupont Company under the trademark KEVLAR.
Adjacent the strength members 16, 1 6 are a pair of optical fibres 18, 1 8 also located on diametrically opposite sides of the cable axis. Any suitable optical fibre composition can be used, but a typical fibre includes a core 1 spa and an outer cladding 1 sub. The fibre is preferably formed so as to exhibit resistance to gamma radiation to minimise radiation-induced optical absorption.
One type of fibre found usable for this purpose includes a core 1 8a doped with germanium and a cladding 1 8b doped with fluorine. The strength members 16, 1 6 and fibres 18, 18 are located in abutting relationship and are helically twisted about the cable axis.
The bundle formed by the strength members 16, 16 and fibres 18, 18 is wrapped with fibre cord strength members 20 to protect the optical fibres. The fibre cords 20 can also be aramid fibres sold under the trademark KEVLAR, but in that case are smaller cords of about 1420 Denier.
Preferably, the strength members 20 are helically wrapped around the bundle of strength members 1 6 and fibres 1 8. Around the strength members 20 is formed a conventional sheathing 22 that holds the strength members 20 in place and provides additional protection for the fibres. The sheathing 22 can be a composite of paper or polyester wrapped around the strength members 20, and an extruded jacket. This specific structure is not illustrated as it is generally conventional. It should be specifically understood that other sheathings can be used.
In accordance with this invention, the sheathing 22 is wrapped with heat insulating material 12 of sufficient thickness to withstand anticipated heat levels in a thermal explosion. The heat insulating material 1 2 is a glass fibre material commonly referred to as fibreglass. The fibreglass is preferably coated with a fluorocarbon, frictionreducing material such as TEFLON (R.T.M.). In this way, friction resistance is reduced during the fabrication of the cable. This fibreglass can be obtained in the form of a yarn or a tape and is usable in either form. If desired, the fibreglass yarn can be braided into a woven material and can be used in this form. The fibreglass is preferably also helically wrapped around the sheathing 22. Other material suitable for use as the heat insulating material 12 is an organic tape such as aramid or polytetrafluoroethylene.
The sacrificial, flame retardant jacket 14 is extruded over the fibreglass 1 2 and can be a flame-retardant polyurethane material such as that sold under the trademark ESTANE sold by B.
F. Goodrich or HALAR sold by Allied Chemical.
HALAR is a fluoro polymer resin comprising a oneto-one alternating copolymer of ethylene and chorotrifluoroethylene. This material is ablative in that it vaporises at high heat, but other types of flame-retardant materials can be used. For example, materials that char rather than vaporise could also be used. In some instances, the use of the sacrificial jacket may not be necessary. In those instances, the heat insulating material should be made thicker to help absorb the initial heat generated during the blast.
During a nuclear explosion, there is first developed a thermal flash in the form of intense light of about 12 to 20 second duration. This light will ignite the exposed surface of the sacrificial jacket 14 causing it to vaporise or char. After the flash, there is a high wind that will extinguish the combustion of the jacket. Thereafter, the intense heat following the blast is resisted by the insulating material 12 which is left substantially intact as is the cable 10. Because the cable 10 is intact, it can operate as it was designed to withstand normal environmental and use conditions.

Claims (11)

1. An optical fibre cable comprising a sheathing, optical fibres contained within the sheathing and a heat-insulating material surrounding the sheathing.
2. An optical fibre cable comprising a sheathing, optical fibres contained within the sheathing and a heat-insulating material surrounding the sheathing, wherein the heatinsulating material is in turn surrounded by a sacrificial jacket which is flame-retardant.
3. An optical fibre cable in accordance with claim 1 or 2 wherein the heat-insulating material is fibreglass.
4. An optical fibre cable in accordance with claim 1 or 2 wherein the heat-insulating material is an organic tape selected from the group consisting of aramid and polytetrafluoroethylene.
5. An optical fibre cable in accordance with claim 3 wherein the fibreglass is coated with a friction-reducing material.
6. An optical fibre cable in accordance with claim 3 wherein the fibreglass is helically wrapped around the sheathing.
7. An optical fibre cable in accordance with claim 3 wherein the fibreglass is braided around the sheathing.
8. An optical fibre cable in accordance with claim 3 wherein the fibreglass is in the form of tape wrapped around the sheathing.
9. An optical fibre cable in accordance with claim 2 wherein the flame-retardant jacket is polyurethane.
10. An optical fibre cable in accordance with claim 2 wherein the flame-retardant jacket is ablative.
11. An optical fibre cable in accordance with claim 2 wherein the flame-retardant jacket chars when exposed to extreme heat.
1 2. An optical fibre cable substantially as described with reference to the accompanying drawings.
GB08328212A 1982-10-28 1983-10-21 Optical fibre cable Withdrawn GB2129158A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US43739382A 1982-10-28 1982-10-28

Publications (2)

Publication Number Publication Date
GB8328212D0 GB8328212D0 (en) 1983-11-23
GB2129158A true GB2129158A (en) 1984-05-10

Family

ID=23736241

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08328212A Withdrawn GB2129158A (en) 1982-10-28 1983-10-21 Optical fibre cable

Country Status (4)

Country Link
DE (1) DE3338485A1 (en)
ES (1) ES275332Y (en)
GB (1) GB2129158A (en)
NO (1) NO833763L (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5131064A (en) * 1991-02-19 1992-07-14 At&T Bell Laboratories Cable having lightning protective sheath system

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1172272A (en) * 1967-01-09 1969-11-26 Standard Telephones Cables Ltd Coaxial Transmission Line
GB1461540A (en) * 1975-01-21 1977-01-13 Standard Telephones Cables Ltd Optical fibre cables
GB1483845A (en) * 1975-08-14 1977-08-24 Standard Telephones Cables Ltd Land lines
GB1501800A (en) * 1975-11-14 1978-02-22 Fort F Optical conductor cable
GB1568546A (en) * 1976-02-25 1980-05-29 Western Electric Co Optical communication cable
GB2036361A (en) * 1978-12-04 1980-06-25 Bendix Corp Reinforced Optical Fiber Conductor and Optical Fiber Cable Incorporating such Conductors
GB2064811A (en) * 1979-11-22 1981-06-17 Noane Le Optic fibre submarine cable
GB1601086A (en) * 1977-05-27 1981-10-21 Siemens Ag Communications cables comprising glass optic fibres
GB2074753A (en) * 1980-04-24 1981-11-04 Philips Nv Electro-optic cable
EP0041097A1 (en) * 1980-05-30 1981-12-09 W.L. Gore & Associates, Inc. Ribbon cable
GB2088584A (en) * 1980-11-28 1982-06-09 Pirelli Cavi Spa Overhead electric cable
GB2105486A (en) * 1981-09-01 1983-03-23 Standard Telephones Cables Ltd Optical fibre cables
GB2116746A (en) * 1982-03-18 1983-09-28 Bicc Plc An improved flexible stranded body

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1172272A (en) * 1967-01-09 1969-11-26 Standard Telephones Cables Ltd Coaxial Transmission Line
GB1461540A (en) * 1975-01-21 1977-01-13 Standard Telephones Cables Ltd Optical fibre cables
GB1483845A (en) * 1975-08-14 1977-08-24 Standard Telephones Cables Ltd Land lines
GB1501800A (en) * 1975-11-14 1978-02-22 Fort F Optical conductor cable
GB1568546A (en) * 1976-02-25 1980-05-29 Western Electric Co Optical communication cable
GB1601086A (en) * 1977-05-27 1981-10-21 Siemens Ag Communications cables comprising glass optic fibres
GB2036361A (en) * 1978-12-04 1980-06-25 Bendix Corp Reinforced Optical Fiber Conductor and Optical Fiber Cable Incorporating such Conductors
GB2064811A (en) * 1979-11-22 1981-06-17 Noane Le Optic fibre submarine cable
GB2074753A (en) * 1980-04-24 1981-11-04 Philips Nv Electro-optic cable
EP0041097A1 (en) * 1980-05-30 1981-12-09 W.L. Gore & Associates, Inc. Ribbon cable
GB2088584A (en) * 1980-11-28 1982-06-09 Pirelli Cavi Spa Overhead electric cable
GB2105486A (en) * 1981-09-01 1983-03-23 Standard Telephones Cables Ltd Optical fibre cables
GB2116746A (en) * 1982-03-18 1983-09-28 Bicc Plc An improved flexible stranded body

Also Published As

Publication number Publication date
GB8328212D0 (en) 1983-11-23
DE3338485A1 (en) 1984-05-03
NO833763L (en) 1984-04-30
ES275332Y (en) 1984-12-01
ES275332U (en) 1984-04-16

Similar Documents

Publication Publication Date Title
US5390273A (en) Flame resistant optical fiber cable with optical fibers loosely enclosed in tubes
US4653851A (en) Fire resistant fiber optic cable
US4818060A (en) Optical fiber building cables
US5917977A (en) Composite cable
US4687294A (en) Fiber optic plenum cable
US4547626A (en) Fire and oil resistant cable
US5268971A (en) Optical fiber/metallic conductor composite cable
US4772091A (en) Light waveguide cable
US5495546A (en) Fiber optic groundwire with coated fiber enclosures
US4781433A (en) Optical fiber plenum cable and methods of making
US5343549A (en) Riser optical cable having filling compound
US4304462A (en) Thermal hardened fiber optic cables
US4896940A (en) Optical fiber cable for use in high temperature contaminating environment
EP0193780B1 (en) Submarine cable for optical-fibres telecommunications
EP0193779B1 (en) Optical-fibres telecommunications submarine cable
WO1996023239A3 (en) Polypropylene-polyethylene copolymer buffer tubes for optical fiber cables and method for making the same
GB2360853A (en) Micro composite fiber optic/electrical cable
EP0814355A1 (en) Lightweight optical groundwire
CA1267009A (en) Composite overhead stranded conductor having a filler between optical fibers and a protective tube
EP0306204B1 (en) Optical fiber cable for use in high temperature contaminating environment
EP0361312B1 (en) Light energy transmitting optical fiber cable
EP0151179B1 (en) Flame-resistant plenum cable and methods of making
CN220065223U (en) Anti-extrusion anti-torsion photoelectric integrated fire-proof cable
GB2129158A (en) Optical fibre cable
KR20020074642A (en) A riser rated optical fiber cable

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)