Flames at EJ Shanley’s could be extinguished by the end of today as crews from the scrap yard continue to help firefighters tackle the blaze.
The fire at the Shails Lane site has burned since Saturday morning, with Wiltshire Fire and Rescue Service crews maintaining a continual presence at the scene.
Alan Harper, Wiltshire Fire and Rescue service group manager, arrived at the site this afternoon to oversee proceedings and said the fire could soon be fully extinguished.
He said: “I’ve come to check the progress and see how long it’s likely to continue, and looking at the fire we are hoping we can deal with the majority of it today.
“There’s not a huge amount of burning left in the stacks, but estimating it is a bit tricky.
"We would like to get it out by this evening, but it may be we have to come back tomorrow.
“Because of the nature of the stuff involved we need to rely on the crew from Shanley’s with their large grabs.”
Shails Lane is also due to reopen to traffic again soon.
A team of Shanley’s employees have worked continuously at the site, using diggers to clear wreckage away from the source of the fire.
Mr Harper said: “We’re using large grabs to pull it out and break it down, so we can move on to the next pile.
“It’s a bit of a slow process as it relies on Shanley’s using their grabs to deal with the burning material, and they have been working since it started on Saturday morning.
"Two new crews have just arrived, and they’ll be here until about 5pm, then we will make a decision as to whether Shanley’s will work on.”
While investigations are still ongoing, firefighters believe they have traced the initial source of the fire to one of the yard’s scrap compactors.
Mr Harper said: “The initial information given by the first attending manager suggests it was part of the processor compacting all the materials.
“The process of compacting caused something within it to ignite, and unfortunately before they could deal with it, it spread to the stack, and now here we are.
“It’s not very usual for fires to start in that way, but it can happen.”
He repeated advice for nearby neighbours to keep their windows closed, but stressed there was no risk from any remaining in smoke.
“As time goes on the incident is cooling down, and the quantity of smoke will decrease as we go forward,” he said.
“The problem is when we uncover a hotspot that will produce more smoke.
“More than anything that’s what’s causing difficulties, but we are hoping there shouldn’t be too many problems beyond that.”
At its height over 40 firefighters worked to tackle the blaze, which produced a thick column of smoke visible from as far away as Gloucester.