By SOUTH SURVEYING AND MAPPING INSTRUMENT CO.,LTD.
Metros Help to Transport Large Numbers of People Rapidly. Transportation is the soul of urban cities, as sustainably keeping citizens moving inside downtown is more important than ever. In other words, transport and mobility have played a key role in modernized metropolises full of vigor and variety, as a result of which the bustling and hustling of busy cosmopolises are in dire need of an extensive road transport system allowing higher capacity of passenger flow while less land use and environmental impact.Read more
Apparently, metro, or colloquially as subway and underground, is such an ideal type of public transport effectively offsetting certain limitations of buses, trams and commuter rails such as time control, transfer convenience and so on.
(Note: the 2 pictures below were borrowed from internet.)
(Fig 1 & 2, heavy traffic on road surface and easy move on designated rails)
Guangzhou Moves Up to No.3 in World’s Metro Line Length Rankings.
Guangzhou, situated at the heart of the most-populous built-up metropolitan area in southern part of China, just announced the grand opening to traffic of its 61.5-kilometer metro Line 21 two weeks ago, allowing the city to reach a total of 513 kilometers of track throughout the entire metro system. Since its official operation, Guangzhou has ultimately surpassed London (402 km) and New York (394 km) in terms of urban metro line mileage ranking No. 3 in the world, next to Shanghai (705 km) and Beijing (626 km).
(Note: the 3 pictures below were borrowed from internet.)
(Fig. 3, fast running trains of Line 21)
(Fig. 4 & 5, the 78,600-square-meter Tianhe Park Station tops itself Asia’s biggest one in size.)
South Takes Part in This Constructive Project.
This essay intends to tell you that South has spared no effort in dedication to the rail engineering (see Fig. 7) of this high-profile eastbound metro route featuring the longest line in the city as well as a combination of regular and express trains. As shown in 2 color boxes in the picture (see Fig. 6) below, 2 segments of the metro line (yellow box part: Yuancun Station to Shuixi Station, and orange box part: Zhucun Station toZengcheng Square Station), covering a length of nearly 80 km (2 directions) in total, were assigned to South for some specialized survey tasks inclusive of CPIII control network (also known as foundation pile control network) establishment, track geometry measurement, track slab adjustment, etc. Rome was not built in a day; and so was such a huge transportation infrastructure. South accomplished its own missions of Zhucun Station to Zengcheng Square Station during October 2017 to June 2018, and Yuancun Station to Shuixi Station during March 2018 to July 2019.
(Fig. 6, line map of Guangzhou Metro No.21 and 2 mission parts for South)
(Fig. 7, overnighted working on the site with the specialized equipment)
CPIII Control Network Establishment
As the most fundamental control network in railway engineering, it’s of high significance to midline stake-out, concrete base moulding, track slab adjustment and long track precise adjustment. In the job (see Fig. 8 & 9), the engineers were committed to the professional rail survey from plane control, elevation control to densified pile measurements. And this methodology was previously utilized in high-speed railway lines of Shanghai-to-Nanjing and Harbin-to-Dalian, and subway lines of Shenzhen Metro No.6 and Guangzhou Metro No.14.
(Fig. 8 & 9, CPIII measurements with digital levels mainly)
Track Geometry Measurement & Track Slab Adjustment
Before the concrete base moulding came in practice, the CPIII measurement results were fully accredited by the employer. Then followed the track geometry measurement and track slab adjustment using MEASLLEY products. South MEASLLEY (a compound word of Measuring Trolley) was particularly designed to deal with track alignments in terms of inner and outer geometric conditions. With this specialized system, the engineers managed to find out the clutch readings like superelevation, horizontal displacement, warping, orientation, etc. Failures to comply with such slight adjustments would lead to bad performance in operational stability of the trains and ride comfort of the passengers. Such jobs were done before in high-speed railway lines of Chengdu-to-Guiyang and Shanghai-to-Hangzhou, and subway lines of Shenzhen Metro No.4 and Changzhou Metro No.2.
(Fig. 10 & 11, track geometry measurement and track geometry measuring trolley)
Long Track Precise Adjustment
Upon completion of long track welding, such long tracks would take the place of stand-in short ones. Again, the geometric data measured by MEASLLEY served as the reference of adjusting the final alignments with deviations of gauge, superelevation and orientation not more than 1 millimeter compared to scheme specification individually. Still, high-precision adjustment is very crucial in bringing low drag, little noise, reliable stability, and ultrahigh comfort to the riders. MEASLLEY, the keen partner of track adjustment, could be used in the railway construction stage and routine maintenance stage both.
(Fig. 12, well-adjusted long tracks ready for standard operations)
South Continues Efforts in Rail Engineering for the Survey Community.
Guangzhou is now facilitating a seamless metro network system consisting of 14 lines providing more convenient ways to move around the city and triggering higher residential and economic growth, though it’s still expanding in coming decades. Believe it or not, South rail survey technologies might stay behind when you are travelling in a metro line or a high-speed train in China. And South will be continuing its hard work challenging specialized high-precision measurement in rail engineering for the motherland and the world.
(Note: the 2 pictures below were borrowed from internet.)
(Fig. 13, happy city life with metro functioning in metropolises)
(Fig. 14, survey work always goes with rail engineering.)
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