SURVEY work on one of Old Town's most familiar landmarks has been carried out this week.

Architectural experts have been working in the air and on the ground around the tower of Christ Church in Old Town.

More than 150 years of harsh weather and pollution have taken their toll on the roof and brickwork of one of Swindon's most important landmarks.

This week, engineers measured the church and accurate plans have been drawn up of the interior and exterior.

Peter Wightman, an engineer for Sterling Surveys based in Grayshott, Surrey, said the project was comparatively small.

"We are concentrating on the tower of the church for this survey. Compared to other projects we have worked upon, this one is quite small.

"We have done a lot of work on Windsor Castle, and the Tower of London."

On Thursday, a large hydraulic hoist was brought in to allow the engineers close to the main tower. The hoist carried two engineers using a special surveying camera for a photogrammetric survey.

The engineers take eight shots on each of the four sides of the church.

Once complete, the shots along with the measuring data are put into a computer programme, which produces a three-dimensional model.

It is this model that will give the Skyline appeal the information it needs to call for quotations for the main work to be carried out. Paul Brooks, a photogrammetrist for Photarc Surveys in Harrogate, North Yorkshire, said: "We use very accurate cameras to take photographs of each side of the building.

"The pictures are very clear, which allows us to have a close look at each brick.

"Those pictures will allow us to make a 1/50th scale model in the computer which will be used by architects to see what repairs are needed."

David Vowles, a member of the parochial church council building sub committee said he hoped that once work began more interest would be generated.

Mr Vowles said: "We are very pleased that progress is now being made on the project.

"It means that once we have the results in a few weeks' time we will be able to start tendering for materials. I hope that now people can see that things are happening that it might generate some enthusiasm for the appeal."

The Skyline Appeal was launched in 2001 with the aim of raising around £1.5 million to carry out all the repair work.

So far only £190,000 has been raised and the appeal plans to use an extra £100,000 from the parochial church council funds to begin the essential work on the tower.

aosborne@newswilts.c.uk