Members of Pawtucket Firefighters Local 1261 of the International Association of Fire Fighters, embroiled in a long-running contract standoff with Mayor Donald Grebien, say public safety will suffer for the six to eight weeks that Engine 3 is taken off the road to accommodate repairs at Station 3 on Columbus Avenue. Erik Cordeiro, vice president of the union, said Engine 3 was responsible for about 3,000 service runs last year, and combined with other changes, the whole east side of the city is now left with little coverage. Areas such as Bishops Bend are particularly at risk, he said, with longer response times anticipated. Cordeiro said the original plan described by Chief William Sisson was to leave Engine 3 in service during the upcoming temporary closure, but that changed after an informational picket by firefighters late last month.