The remote-controlled devices, which have never been used in Scotland before, work inside the gas pipes to spot leaks and carry out repairs.

Less of the road has to be dug up, reducing the need for contraflows.

A pioneering trial took place in Dalkeith Road last week, and proved so successful that the device is this week being used in George Street to inspect around half a mile of metal pipeline.

The underground robots are being used by SGN, a company which used to be known as Scotia Gas Networks and Southern Gas networks.

SGN said the use of the technology minimised disruption as it only needed to excavate at four locations in Dalkeith Road during the 11 week work schedule.

The Cisbot, created by US firm ULC Robotics, is a robot that specialises in repairing cast iron pipeline joints. It is easily collapsible in order to launch it into the pipe, and once inside, the robot’s seven cameras enable it to be remotely-controlled to travel a length of 150m.

When it reaches a lead yarn joint, it will position itself and drill into the joint to inject a sealant to repair holes in the joint, but it can only go in straight lines at the moment.

In the old days, town gas was made from coal and was of a wetter composition, but after the UK switched to natural gas in the 1970s, over time the gas has dried out the yarn in the joints, causing many of the pipes to leak.

Rather than wait for gas leaks to happen, SGN works to pre-emptively check pipes and reseal the old joints, but the conventional way to do this involves closing off roads and digging trenches to cut into the joints, which is time-consuming and causes noise pollution and traffic congestion.

To solve this problem, since October 2013 SGN has been trialling robotics technology to help improve gas network remediation, and its latest project is to repair 9km of gas distribution pipes in Edinburgh.

SGN said: “As part of our planning process we have met with City of Edinburgh Council and Lothian Buses. We will continue to work with the authorities and the local community throughout the course our works.

“The use of robotics technology will enable us to complete our work more quickly than ever before with less traffic disruption. In fact, a significant amount of our work will be invisible, as it takes place under the ground.

“The technology enables us to refurbish joints on some of our larger iron gas mains without the need to dig multiple excavations in the road or take the gas main out of service. The robot refurbishes the gas mains from inside the pipe. The use of robotic repairs means that we can substantially reduce the amount of time we’re working in the road. The aim is that using this technology will result in less traffic congestion, noise pollution, and disruption to local residents and businesses.”