ITU-T L 30-2007 Markers on marinized terrestrial cables《海陆电缆标记 学习研讨会6》.pdf

1、 International Telecommunication Union ITU-T L.30TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2007) SERIES L: CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT Markers on marinized terrestrial cables ITU-T Recommendation L.30 ITU-T Rec. L.30 (11/2007) i I

2、TU-T Recommendation L.30 Markers on marinized terrestrial cables Summary ITU-T Recommendation L.30 describes the types of markers that can be applied on marinized terrestrial cables (MTC) and related land cables (considered as part of MTC). Moreover, markers also warn of approaching joints, transiti

3、ons and/or any relevant variation on the cable that can be useful for future inspections, cable protection and/or repairing. Both the materials and colours used for markers and their application points, are described. Source ITU-T Recommendation L.30 was approved on 6 November 2007 by ITU-T Study Gr

4、oup 6 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. L.30 (11/2007) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunicat

5、ion Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (

6、WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fal

7、l within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Re

8、commendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language su

9、ch as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recomme

10、ndation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of appro

11、val of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB p

12、atent database at http:/www.itu.int/ITU-T/ipr/. ITU 2008 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. L.30 (11/2007) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Land cables . 1 4 Marinized terre

13、strial cables. 1 4.1 Type of markers 2 4.2 Marker material 2 4.3 Distance marker 2 4.4 Factory joint marker . 2 4.5 Warning markers 3 4.6 Transition marker . 3 4.7 In-line joint marker. 4 5 Requirements for numbered and lettered tapes 4 6 Alternative markers 4 iv ITU-T Rec. L.30 (11/2007) Introducti

14、on A marinized terrestrial cable is an underwater optical fibre cable construction, based on a conventional multi-fibre terrestrial cable core protected to withstand the marine environment, designed for unrepeated applications, that is, without underwater line amplifiers, hence without the need to c

15、arry electrical power and tested for use in non-aggressive shallow waters, with a varying repair capability. The difference with respect to a repeaterless submarine cable can be found in the definition given, for such a cable, in ITU-T G.972. The purpose of establishing uniform marking techniques an

16、d procedures is to facilitate repairs and restoration of telecommunications in the event of an accidental cable break or natural disasters. As such, markings and procedures contribute to the overall security of the MTC links. ITU-T Rec. L.30 (11/2007) 1 ITU-T Recommendation L.30 Markers on marinized

17、 terrestrial cables 1 Scope This Recommendation deals with: materials, dimensions and colours of tapes as well as their application points to be utilized for MTC marking; fundamental considerations to avoid any possible impairment to cable performance, and in their handling; requirements for numbere

18、d and lettered tapes. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references

19、are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a d

20、ocument within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.972 ITU-T Recommendation G.972 (2004), Definition of terms relevant to optical fibre submarine cable systems. 3 Land cables Land cables are considered as part of marinized terrestr

21、ial cables. For identification purposes, the outer sheath of the cable should preferably have a distinctive colour (for example, yellow, orange, etc.), taking into account any requirements for UV protection, or a proper marking, if applicable. In addition, the outer drum surface should be marked, as

22、 an example, “MARINIZED CABLE X-Y land section“ (X-Y being the connection section length) on both sides of the drum. It is also recommended that the outer drum marking details the number and type of fibres contained in the cable as well as its overall weight. 4 Marinized terrestrial cables While cer

23、tain marker colours are presented in the following text, the actual colours may need to be different depending on the colour of the cable. In all cases, the markers shall be distinctly recognizable against the colours of the cable, and the colour coding scheme for each particular MTC link shall be d

24、ocumented. 2 ITU-T Rec. L.30 (11/2007) 4.1 Type of markers The following markers, as appropriate, can be applicable to marinized terrestrial cables. Each marking should be applied without any impairment to cable performance and without affecting their handling operations (i.e., loading, laying and r

25、ecovering/repairing). They include: a) distance markers; b) factory joint marker; c) warning markers; d) transition markers; e) in-line joint marker. 4.2 Marker material The material should be waterproof self-adhesive tape, typically of about 50 mm width and of 125 m nominal thickness. The material

26、should be clearly identifiable after being immersed for 24 hours in a saturated aqueous solution of H2S at a temperature ranging between 20C and 25C. Moreover, for laying, maintenance and recovery purposes, the materials used should be waterproof and corrosion resistant during the cables operating l

27、ifetime. Besides, such materials should also be proofed against marine growth and sea vegetation. 4.3 Distance marker A distance marker shows the cable length from a point of origin with numbers and/or characters. A distance marker should be applied to the cable typically every one km with an accura

28、cy within 0.25%. The marker should consist of double-wrapped numbered and/or lettered tapes affixed to the cable as shown in Figure 1. Figure 1 Distance markers (km) Where the marker is applied over armoured cable, the numbered and lettered tapes should be affixed over a helical lapping typically of

29、 yellow tape applied with a 50% overlap. The direction of the counting should be as shown in Figure 2. Figure 2 Direction of marker count 4.4 Factory joint marker The factory joint marker should be applied to a cable joint referring to a complete, or portion of, a jointing of an optical fibre inside

30、 the cable and/or the protective elements of the fibre (i.e., tapes, armouring, etc.) during the manufacturing process that degrades the overall mechanical or dimensional properties of the original cable and requires attention during laying and maintenance handling operations. ITU-T Rec. L.30 (11/20

31、07) 3 A double-wrapped number tape or tapes should be affixed centrally, typically over the 450-mm middle wrapping. The joint marker should consist typically of five individual bands of blue tape affixed to the cable as shown in Figure 3. The middle band should consist of a helically lapped blue tap

32、e with a 50% overlap and with its extremities covered typically by a 50-mm wide double wrapping of the same type of tape. The four outer bands should consist typically of 50-mm double wrappings of blue tape. Joints should be numbered sequentially. Figure 3 Joint markers 4.5 Warning markers A warning

33、 marker is applied to warn of the approach of an unusual point on cables, such as joint box or branching unit. A warning marker should consist typically of two bands of coloured tape affixed to the cable as shown in Figure 4. Each band should consist typically of a helically lapped tape with 50% ove

34、rlap and with its extremities covered typically by a 50-mm double wrapping of black tape. The colour of the markers is typically: red, at 6 km; yellow, at 2 km; light green, at 1 km. The 6-km warning marker is not required where the length of the cable/link is less than 10 km. Figure 4 Warning marke

35、rs 4.6 Transition marker The transition marker should be applied to warn of a change in cable type, for example from single armoured cable to double armoured cable. Cable transition can be achieved using either a transition cable or transition joint as mentioned in ITU-T G.972, item 5015. The transi

36、tion marker, where permitted, typically should consist of two bands of helically lapped tape applied with a 50% overlap, with a width of typically 150 mm, on either side of the transition. 4 ITU-T Rec. L.30 (11/2007) 4.7 In-line joint marker The in-line joint marker should be applied to a cable end

37、next to a joint box in order to identify its sequential number. The joint marker should consist typically of five individual bands of blue tape affixed to the cable as shown in Figure 3. The middle band should consist of a helically lapped blue tape with a 50% overlap and with its extremities covere

38、d typically by a 50-mm wide double wrapping of the same type of tape. The four outer bands should consist typically of 50-mm double wrappings of blue tape. A double wrapped number tape or tapes should be affixed centrally, typically over the 450-mm middle wrapping. Joints should be numbered sequenti

39、ally. 5 Requirements for numbered and lettered tapes The tape should be typically yellow/orange or blue, according to the colour identification in Table 1, with the size and colour of characters (letters and numbers) typically of 24 mm black, printed at intervals typically of not more than 12.5 mm t

40、hroughout its length. When more than one character is required, the printed tapes should be affixed so that the characters are side by side. The tapes should adhere firmly without entrapped air. Table 1 Tape colour identification Tape application point Colour Distance marker Yellow Factory joint mar

41、ker Blue Warning marker Red/yellow/light green inside black marker limits Transition marker Yellow In-line joint marker Blue 6 Alternative markers Alternative markers can be considered, which are equivalent to the above, noting the possible advantages of the proposed markers. Printed in Switzerland

42、Geneva, 2008 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series D General tariff principles Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and me

43、dia, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installation

44、 and protection of cables and other elements of outside plant Series M Telecommunication management, including TMN and network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Telephone transm

45、ission quality, telephone installations, local line networks Series Q Switching and signalling Series R Telegraph transmission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems