It means members of the RMT union will strike for 48 hours from 18:30 BST on Wednesday over concerns over safety, job losses and buffet services.
The union said the firm was "going through the motions" in the talks.
The strike is likely to affect passengers attending the second day of the first Ashes test match in Cardiff.
The five-day game, at the The SWALEC Stadium, is due to begin on Wednesday morning.
RMT General Secretary, Mick Cash, said: "RMT has made every effort to secure a series of very basic assurances from FGW over jobs, services and safety as a result of the introduction of the new Hitachi fleet and they have shown no intention of addressing those issues in the talks today.
"RMT is angry and disappointed that the company have ignored the massive vote for action by their staff and have instead opted to plough ahead with a series of actions that will decimate jobs, services and safety.
"As a result of FGW collapsing the talks in this cavalier fashion the action goes ahead as planned.
"It is frankly ludicrous that East Coast, who are introducing the same trains, have given us the assurances we are seeking but FGW have ignored us and are crashing on with the ripping out of buffet cars and the threat to safety-critical station and train staff, purely to maximise the profits from new trains bought for them by the British taxpayer."
In a ballot held last week 80% of workers supported strike action and 92% other forms of action.
First Great Western said the strike would lead to a revised timetable being operated.
The first Hitachi trains will run on the Great Western main line from 2017 and the East Coast main line from 2018.
The new trains are being introduced under the Intercity Express Programme (IEP) on routes between London Paddington and Oxford, Bristol and South Wales.
Talks aimed at settling a dispute over plans to axe guards and buffet cars on First Great Western's new Hitachi Inter City Express trains have broken down.