The 9,640-meter Zhanjiang Bay undersea tunnel, a key engineering feature of the line, set a record for the longest single-head tunneling distance for a large-diameter undersea tunnel in China.

"During the construction process, we faced world-class challenges such as complex undersea geology and high-water pressure," said Zheng Wei, an engineer from the Guangdong Guangzhou-Zhanjiang Railway Co.

The project team adopted several new technologies, including intelligent tunneling, to overcome difficulties during construction, according to Zheng, who participated in the maiden journey on Monday.

The opening of the high-speed rail between Guangzhou and Zhanjiang has provided a boost to modern agriculture in western Guangdong. In the Genzi township of Maoming, famously known as the hometown of lychees, a major farmer surnamed Long was busy inspecting a brand-new packaging production line.

"We are making thorough preparations for next year's lychee season," Long said.

With the opening of the rail line, more people are expected to visit the township.

"Our channels for selling high-quality lychees externally to the Greater Bay Area and beyond will further expand," he said.

Meanwhile, the Shantou-Shanwei railway, also with a design speed of 350 km/h, connects eight districts and counties across the cities of Shantou, Jieyang and Shanwei. It serves as a corridor linking eastern Guangdong with the Greater Bay Area.

The travel time reduction is expected to empower the industrial development of Shantou, a traditional manufacturing and trade base for toys, gifts and garments.

In the Chenghai toy creative industry park in Shantou, a buyer from Shenzhen surnamed Chen was negotiating business in the sample showroom of Alpha Group Co.

"In the past, I had to allocate two days for business trips to Shantou, and it took an additional hour to reach Chenghai district from Shantou South Railway Station," Chen said.

With the opening of the high-speed railway, Chen was able to quickly reach the manufacturing and trade base.

"Now I can select products in the morning, sign deals in the afternoon and return to Shenzhen in the evening," Chen said.

The operation of the two new lines has helped facilitate the construction of a more efficient transportation network in Guangdong during the 14th Five-Year Plan period (2021-25), according to China Railway Guangzhou Group.

Total railway operating mileage in the province has reached 6,433 km. High-speed railways operating at speeds of 200 km/h or more account for 3,411 km, according to the railway company.