There have been some delays on the Norwich to London train line today due to lower speed restrictions put in place on parts of the line due to the hot weather.

From midday today the Greater Anglia mainline service implemented some timetable revisions as a result of the speed restrictions - for the Norwich to London train line this meant that two trains did not stop at Stratford and there have been delays of between five and 10 minutes on some services.

It is expected there will continue to be minor disruptions on the line to the capital until about 7pm this evening.

A Network Rail spokesman said the restrictions had needed to be put in place to prevent damage to some overhead cables.

He explained: 'We are currently in the middle of a �200m+ project to completely replace all the overhead lines on the Great Eastern Main Line between London and Chelmsford.

'While the core section from Liverpool Street to Stratford has been completed, the sections of railway which have speed restrictions in place today have overhead lines dating from the 1950s and 1960s. The wire in these sections can expand and sag in high temperatures and, as a result, it is necessary to reduce speeds in order to avoid damaging the equipment and trains.

'The contingency arrangements put in place today are tried and tested and are designed to minimise both the risk of damage to equipment and trains as well as any disruption to passengers.'

When asked what would happen with the train services if the hot weather continued into the Olympics, he said 'the weather forecast for Friday is very different from today,' and he said the plans in place today were a 'tried and tested contingency plan regularly put in place to deal with the issue.'

A Greater Anglia spokesman said the company had been working with Network Rail to minimise the disruption.

In terms of the Norwich to London services he said the speed restrictions had 'not had a significant impact'.

He said that originally nine services on the Norwich to London line had been revised not to stop at Stratford today but that this had been reduced to two.

'The overall impact on Norwich services is not particularly significant,' he said.

'The delays that have been caused today have been within a few minutes. Not all trains are being delayed but some have been delayed by between five and 10 minutes.'

About tomorrow, he said: 'At the moment we are not expecting to have to make any alterations to services tomorrow. 'We will confirm that on our website later this evening. I think there will still be some speed restrictions in place tomorrow and there could be some minor delays tomorrow if trains are running at low speeds but we are not expecting to make any service revisions.'

When asked about travel over the Olympic period, he said: 'If there are days with speed restrictions, we will look to run the timetable with all the stops at Stratford and work closely with Network Rail to make that happen.'

He also said during the Olympics Greater Anglia was running increased train services on the Norwich to London line with the last train back to Norwich on most days during the Olympics being 00.30am and on this Friday at 1.30am.

He said on the Norwich to London line a Saturday service would be running on Sundays during the Olympics.

For more information about train times visit www.greateranglia.co.uk