220kV Zhoushan to the Mainland Networking Project


 

Characteristics of Record-breaking Screw Channel Long Span: 

 

a.Maximum span of the project is 2756 meters, which ranks first in Asia.

b.The height of the tower is 370 meters, which is the world’s first power transmission tower.

c.Tension section length of the long span is 6.2km, which belongs to the longest tension section of world’s transmission line.

d.The tower of the long span can withstand typhoon of level-16.

e.After the project was completed, there would be 600,000kw electric power continuously flowed from the mainland to Zhoushan in Zhejiang Province, which equivalents to six times that of the current cable transmission capacity.

 

 

 

Introduction of Screw Channel Long Span:

 

Screw Channel Long Span starts from Big Cat Mountain in the north and ends at Main Island of Ningbo in the south with a total length of 6203 meters.

 

Screw Channel Long Span adopts “tension tower-straight line tower- straight line tower- straight line tower” mode, the main span crosses international waterway to Screw Channel, and the distances of the spans are 992-2756-1286-1181 meters in order.

 

Three towers locate respectively on Big Cat Mountain of Zhoushan, Liangmao Mountain of Ningbo and 450 meters east of External Shenma Island on the sea.

 

The height of span tower on Big Cat Mountain and Liangmao Mountain is about 370 meters; the span tower in the sea locates 1270 meters south of Liangmao Mountain and about 450 meters away from External Shenma Island with a total height of 201 meters.

 

Both sides of the transmission line adopt OPGW, four-bundle conductors of JLB23-380.

 

 

 

 

This long span project adopts OPGW together with conductor for sag verification so as to guarantee the vertical distance between OPGW and conductor for Screw Channel Long Span under average annual operating conditions is not less than 17.5m.

 

 

ZTT OPGW & Conductor Space Calculation Statistical Charts

 


Span(m)

500

1000

1500

2000

2500

2756

3000


Conductor Sag(m)

7.3

29.2

69.3

130.3

208.9

256.0

305.1


OPGW Sag(m)

7.5

29.9

69.0

130.0

208.7

255.8

304.9


Tower Head Size(m)

20.0

20.0

20.0

20.0

20.0

20.0

20.0


Space Between Conductor & OPGW (m)

19.8

19.3

20.4

20.3

20.2

20.2

20.2


Regulations Request(m)

7.0

13.0

17.5

17.5

17.5

17.5

17.5