A train apparatus for removing thick blister buildups from an underground fiber conduit used for housing power cables. The train apparatus includes three or more cutting units including an initial, a middle and a final cutting unit having smallest, medium and largest overall cutting diameters respectively. Each cutting unit having a lead guide and six cutting stars each having four cutting blades where the cutting blades on one cutting star are offset with the cutting blades on the other cutting stars. When pulled through the fiber conduit, the lead guide of the cutting units will prevent the cutting unit from going off the center of the conduit and digging itself into the interior sidewall of the conduit. The initial, middle and final cutting units will remove respectively the surface, the intermediate and the underneath portions sequentially. The train apparatus further includes a trailing guide for preventing it from going off center of the conduit and digging itself into the interior sidewall of the conduit. When the train gets stuck inside the fiber conduit and it is necessary to pull it out backwardly, a cable will be attached to the trailing guide for this purpose.