Date: 201704
Local time of day: 1201-1800
Location: ZBW.ARTCC, NH
Light: Daylight
Aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZBW
ATC / advisory: Center ZBW
Second aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Time Pressure; Workload
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Clearance
Detector: Automation Air Traffic Control; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Separated Traffic
Contributing factors: Company Policy; Human Factors; Procedure; Airspace Structure
Primary problem: Human Factors

Narrative: I was working R46 without a Radar Assist. Traffic was fairly routine with the exception of weather re-routes and in-trail restrictions with no back-to-back BWI or DCA aircraft. Aircraft X from had filed J75. Their preferential route was via J48 which had no in-trail restriction. This aircraft sat on the ground on a bad route for 35 minutes and nobody fixed it. If it had been routed via BAF; as it should have been; this never would have happened because they would have been 20 miles north of NELIE over BAF VOR. As I was relieving the 46 controller he mentioned the bad route coming our way. R47 issued the reroute while he was climbing out in their airspace. Because the aircraft was headed towards NELIE; they issued direct TRIBS intersection which put Aircraft X right over NELIE. I took the handoff; climbed the aircraft to FL260 and handed them right to R20; as they were within 10 miles of the border.Subsequently; I took a handoff on Aircraft Y. Typically I would have issued this aircraft direct to CMK; which would have placed him about 10 NM south of NELIE. However; there was a corporate jet at FL400 doing Mach .74 about 30 miles ahead. As I had to provide 20 miles in trail on J75 regardless of type; altitude; or destination; I left Aircraft Y on the route. Aircraft X left my airspace so I suppressed the data block. I climbed Aircraft Y to FL380. Then I took handoffs on 6 BWI arrivals. The flow restriction stated no back-to-back BWI arrivals. I asked my supervisor to talk to Traffic Management Unit (TMU) and ask for guidance on what I should do with these aircraft. I attempted to call ZNY N42 to ask the controller directly for relief. Most of this was taking place in the vicinity of BOS or PVD and that is where my attention was focused. Aircraft Y was approaching the border with R20 and they had yet to accept the handoff. I assumed it was because they were busy trying to blend their flows for ZNY. My supervisor told the R47 controller and myself that we could selectively reroute BWI aircraft down the coast through ZDC. While we were working on this the conflict alert went off with Aircraft Y and Aircraft X. Aircraft Y was climbing through FL241 and Aircraft X was approaching FL250. I vectored Aircraft Y away from Aircraft X and told him to stop his climb and when able return to FL240. The closest proximity that I saw was about 4.5 miles when I got a report from Aircraft Y indicating 1000 feet vertical separation existed.R20 took the handoff. I called them and told them that Aircraft Y was turning back on course; and sarcastically thanked them for calling me about the impending loss of separation. TMU should never had agreed to '20 miles in trail via J75 with no back-to-back BWI or DCA arrivals.' That's a ridiculous restriction. If ZNY needed 40 or 30 miles in trail on BWI and/or DCA aircraft that should have been the restriction. We rerouted 3 airborne aircraft for no real reason. ZNY would have gotten an airplane every 20 miles and who cares what the destination was? This was regardless of altitude.When ZNY decides to take the night off on the backs of ZBW and ZDC they should be called on their bad actions. At a minimum; the J75 in trail should be stratified so that aircraft going further at higher altitude would be separate from aircraft that need to be started down sooner. Pilots need to do a better job of filing the preferential route. A lot of them have the attitude that they will just file whatever and it's our job to fix it. While it is our job; it is their job to file the preferential routes.Our radar Assists need to do a better job fixing bad routes in a timely manner while aircraft are on the ground. The common attitude is 'its close enough; what's the worst that can happen?' Well; a deal can happen. And now the FAA Handbook 7110.65 is changing and we will have to fix routes 30 minutes prior instead of 15. This problem will only get worse. Traffic management Unit was not even monitoring the BWI traffic while there was an in-trail restriction. Need I say more? Despite all of this; I should have told Aircraft Y to expedite through FL270 feet. We are spoiled with the new modern aircraft. Usually a B737 off PVD would cross NELIE above FL300 feet. I'm guessing that because he received a ground delay; Aircraft Y was trading climb rate for forward speed. I should have known better and been proactive.Typically if I hand a slow aircraft to another sector; I watch them for a while beyond my airspace so I don't run them over. Aircraft X was initially in an area; at an altitude where I never imagined he would get run over. Lesson relearned.




Synopsis: ZBW Center Controller reported an aircraft overtook another aircraft resulting in a loss of separation while they were distracted with other coordination.