Summary：The trains were put back into operation at the end of last year after the problems were solved and their quality was approved.

China began to solicit public opinion on railway safety draft regulations that set tighter standards on locomotive parts, signal systems and railway contracts.

The draft, published by the State Council's Legislative Affairs Office on Monday, bans prime contractors from subcontracting railroad projects that involve pillars, beams, rails and protection measures.

In the event of shared projects, prime and sub-contractors would bear joint liability under the draft, which also requires fencing to be installed anywhere a train's speed exceeds 120 kilometers per hour.

Illegal subcontracting played a role in several scandals last year, for example when a former cook was found to have directed other unskilled migrant workers in building a railway bridge in Jilin province.

Yang Hao, a railway expert and professor at Beijing Jiaotong University, said the measure would guard against hiring companies that "have no qualification in railway construction but are able to win bids via wide connections".

After winning contracts, such companies often reap huge profits by subcontracting. If the regulations are adopted, such companies wouldn't have a chance of being awarded a contract, he said.

The draft also requires producers of locomotive switches, signaling equipment, power supplies and safety equipment, to be approved by State authorities.

It would establish the nation's first railway-product recall system.

Producers of locomotive parts would have to suspend production and recall faulty products. If they were found to conceal misconduct or handle the defected products in an inappropriate way, they would be subject to fines and loss of licenses, under the draft.

Faulty equipment has been blamed for a spate of high-speed train incidents that include traffic delays and a fatal crash near the city of Wenzhou in July, 2011, in which a bullet train slammed into a stalled train, leaving 40 people dead.

Yang said that currently, railway products only need administrative approval.

"The examination of products' performance and quality is a mere formality, and is often conducted by parties that share interests with the producers," he said.

Having authoritative third parties to conduct performance tests and quality assurance tests will "help prevent corruption and manipulation", Yang said.

Last year, China CNR Corp, one of the nation's two major train makers, recalled 54 high-speed trains because they reportedly had a higher malfunction rate than allowed by regulation, with a series of power outages and blackouts on the Beijing-Shanghai line in the first month of operations.

The trains were put back into operation at the end of last year after the problems were solved and their quality was approved.

From now to July 18, the public is invited to offer opinions on the draft regulations.

The draft is widely seen as the central government's response to public concern about railway safety, as it includes lessons learned from the deadly Wenzhou train crash.

An extended State Council investigation of the crash concludes there were "serious design flaws" in the control equipment used at Wenzhou South Railway Station.

Those defects were the result of sloppy management. The Ministry of Railways was also found to have violated bidding and technical examination procedures, which allowed flawed equipment to be used at the railway station and on other rail lines.