United were in Essex on Saturday afternoon for their latest in a run of very tough fixtures.
There were welcome returns for defenders Tom Parkes and Danny Grainger, as they came back into the fold following short injury lay-offs, and striker Mark Cullen made his first start for the club at the point of the front line.
Carlisle started well and an early corner from O'Hare caused interest as it dropped invitingly inside the area. It was just too far away from Parkes for him to make a difference and Colchester were able to clear their lines.
The Blues had a fantastic chance to open the scoring with just five minutes on the clock when Scougall came away with possession in midfield. His crossfield pass found Hope in a good area, and he quickly rolled it back for Grainger to deliver.
It was a peach of a cross and Slater was disappointed not to finish it off as he sent a crunching header straight at Gilmartin from close range. The keeper spilled it, and Slater reacted first to backheel it along to O'Hare. He had to stab at it, as Prosser lunged in, and his effort whipped just past the post.
Colchester created a good moment of their own when Eisa twisted and turned on the edge of the box. He got his shot away but Collin dropped low to deal with it.
United broke in numbers from the clearance from the keeper as Cullen flicked it on to meet a run from Hope. The striker had just one thing in mind and he made Gilmartin go full length to deal with the dipping shot.
Midfielder Stefan Scougall had a confident spell of running things in the middle of the park and a cheeky drop of the shoulder took him away from his man with plenty in support. Slater overlapped but his teasing cross was headed clear.
Excellent defending from Gary Liddle, making career appearance number 600, prevented Szmodics from having a clean sight of the target as Eisa worked hard to pick him out with Colchester struggling to find a way through.
A tumble to the floor from Senior brought a shake of the head from the referee as he looked for a penalty after what had been a quiet spell for both sides, and Cullen received the same response as he went down heavily under a challenge from Prosser at the other end.
More good defending from Liddle saw him chest an attempted Nouble through ball safely back to Collin, but Carlisle were a whisker away from taking the lead when O'Hare latched onto a poor clearance from Gilmartin.
He sprinted into the box and a touch from Slater as the cross came in allowed Cullen time to send it back the other way. That was charged down, but the striker set himself for a volley, when the ball looped into his path, and that fizzed angrily towards the bottom corner. Kent stretched out a leg and he was extremely relieved to see his intervention cause the ball spin just past the gaping target.
A 24-yard Colchester free kick was wasted by Eisa as he cracked it over the wall just before the break, and it remained a very finely balanced game as the teams headed down the tunnel for the half-time team talk.
The U's came out of the blocks firing for the second half but more strong defending kept them at arm's length. Carlisle came up against a similar kind of defensive wall as they tried to make things happen with Hope and Scougall thwarted as they worked hard to open the game up.
A towering run from Kent saw him change defence into attack as he surged through midfield with the ball at his feet. Nouble took over and his cross bounced untouched beyond the far post.
United caused more danger when Grainger bent a free kick into the mix. It was put behind by Prosser as Gerrard jumped high.
Cullen almost found a way through as he beat his man and then aimed a low pass at O'Hare, but Vincent-Young was across to close it down before the nippy wide man could make it count.
Carlisle stayed forward in numbers for the corner and Etuhu was on hand to recycle the pass as it was cleared from the box. O'Hare was in space and his precise low cross was contested by Cullen as he made a move. The ball spun loose from the challenge and Hallam Hope kept his eye on it before notching his eleventh of the season with a deflected finish.
The U's sent men forward, without managing to test Collin between the sticks, and it was United who should have extended their lead when Scougall sparked another good attack. Cullen shielded a pass to bring Liddle into play, and his cross appeared to be perfect for Hope. The forward went for power and his first-time effort sailed over the bar.
Corner deliveries went begging for the hosts as more and more men were pushed into attacking areas, with Prosser going closest when he glanced a whisked delivery just over the bar.
The big defender was even closer moments later when he spun to volley a downward header from a half clearance from Slater. Collin stood his ground and waited to gather it in.
Substitute Nathan Thomas looked to make an impact with a run from his own half, but his shot from distance was always rising high as the game remained nip and tuck.
One of many Colchester deliveries was finally made to count late in the day when a drilled cross fell invitingly for Kent to volley. He was unmarked and he had time to prod it home before the defence could recover their shape.
Szmodics almost provided a late sting when he sent a rasper across Collin and just behind, and a late Grainger corner somehow squirmed past the post in time added on, when Parkes jumped to meet itbut it ended as a share of the spoils for two teams who had put on an excellent display.
Colchester United - Kent (84)
Carlisle United - Hope (57)
Colchester United - Jackson (39), Kent (52)
Carlisle United - Cullen (41), Scougall (60), Gerrard (64)
Colchester United - Gilmartin, Jackson (Norris 75), Prosser, Kent, Senior, Szmodics, Wright (Dickenson 69), Vincent-Young, Stevenson, Eisa (Mandron 69), Nouble. Subs - Barnes, Roberts, Eastman, Dunne.
Carlisle United - Collin, Liddle, Gerrard, Parkes, Grainger, Slater, Etuhu, O'Hare (Jones 79), Scougall (McCarron 85), Cullen (Thomas 69), Hope. Subs - Gray, Miller, Kennedy, Grant.
Referee - Mr Trevor Kettle
Attendance - 3,626 (319 away fans)