The directors had only borrowed the railway from Zimmerman for the week of celebration but during January negotiations began to turn the line over to the company proper. Zimmerman, naturally, insisted that the line was not yet complete according to the original contract. The deal was finally reached, with Zimmerman receiving payment for much of his rolling stock and an adjudicated sum to cover the arrears in payments from the company to the contractors.

Through 1855 and '56 the railway was managed by D'Arcy Boulton and was remarkably successful, given that it was usually only operating between Harwood and Cobourg, with steamers filling in the gap to Peterborough. House lots in Harwood rose from $3 an acre to over $400. In February, 1855, E. Vivien Harwood advertised, "A Great Chance for Capitalists and Others" in The Cobourg Star, seeking to attract "retired gentlemen, Professional men, Merchants and others" for her Harwood lots. The contractor's chief engineer, Ira Spaulding, was sacked and replaced by John Fowler who began filling in large parts of the bridge, seeking to create a solid embankment stretching out from each shore with two artificial islands in the centre near the swing bridge. By March the company was proclaiming that soon the line would again be open to Peterborough.

Private investors and the Town of Peterborough both balked at the idea of sinking more money into what was becoming all too literally the mud of Rice Lake. Mr. Boulton's connections in government went some way to overcome the problem by allowing him to delve into something called the Marriage Licence Fund of Upper Canada, a highly irregular procedure which caused raised eyebrows even in that free-wheeling era. This realized some 10,000 pounds but the railway still didn't have enough to completely fill in the cribs under the bridge.

Peterborough's attitude was somewhat short of helpful. Soon the Port Hope Millbrook and Lindsay line would build a spur to include Peterborough, a move which would thoroughly undercut the Cobourg line, as the Port Hope line would be entirely on land. In 1859, when new directors took over the Cobourg road, they announced that soon the line would be "in good order and that trains will run regularly as heretofore." To which The Peterborough Review sniffed that "the statement made at this end of the line differs somewhat from the above," and that the Cobourg line was to be "precluded, under threat of heavy penalty" from carrying passengers, and that, if run at all, it would be restricted to freight. This was quite acceptable to Peterborough as, for many years, their exports over the line had vastly exceeded the imports coming up from Cobourg. And they had yet to sink a penny of their on money in railroads while the two harbour towns were mortgaging their future to secure trade with the inland waterway which Peterborough dominated.

By this time the trains rarely crossed the bridge without a team of company engineers inspecting the bridge after each crossing to determine if another crossing could be made with safety. On one memorable occasion, Sheriff Ruttan of Northumberland County was noticed sitting in a rear car of a train coming from Cobourg (Bio on Ruttan). An official of the railway noticed him and feared, perhaps, a snap inspection. As the train approached Summit, the station at the height of land, there was a sudden "retrograde" movement, and the sheriff found himself coasting quickly backward towards town in what was now his own private car, while the rest of the train hastened to Harwood, there to put things in better order as best they could. It is unlikely that the sheriff was ever in any great danger. The Cobourg Railway was known to move, at best, at such a speed that it was not uncommon for young people to descend from a front coach while the train was moving, pick some strawberries from the verge of the tracks and ascend the last coach as it came by. Indeed, Sheriff Ruttan went on to invent a novel form of air conditioning, unique for its time, the inspiration for which he ascribed to sitting in the hot sun in a Cobourg railway carriage.

Indeed, railway carriages became one of the more lasting benefits to Cobourg from the railway scheme. Before the rail-way line was complete the company contracted a young machinist named James Crossen, who worked at a foundry on College Street just behind St. Peter's church, to build several flat cars for hauling lumber. Mr. Crossen did so, then went one better and designed a passenger car. The railroad liked the car and commissioned more, whereupon Mr. Crossen built a new foundry up in the derelict Victoria Square area of town near the Grand Trunk Railway line and went into full operation.

Mr. Crossen's railway cars became so famous that, thanks in part to Sir John A. Macdonald's National Policy of tariffs on industrial goods, Mr. Crossen's cars drove the even more famous Pullman cars out of the Canadian and ultimately several international markets. Long after the railway had died, Mr. Crossen's cars were still coming off the line in one of Cobourg's most successful industrial ventures. A replica of the rear end of one of Mr. Crossen's luxurious dining cars can be glimpsed even today, poking out onto the veranda of James Crossen's son's house on George Street. [More on Crossen's House - On Business (by Merrilees) - plus more on Business (by Rafuse)]

"Hoorah for Peterborough!... Boys, come and stand on the wharf at 10 and 4 o'clock and see the sight — 16 cars loaded and emptied daily. Three cheers for Peterborough! Hoorah!" said one correspondent to The Star, noting that some 100,000 board feet of lumber was now passing through Cobourg harbour per day, and that 870 passengers had used the train in May alone. In July Mr. Boulton began issuing weekly reports on their progress, claiming 1,918 passengers for July with 5,396 tons of freight and 136.5 cords of wood. In the 1857 report to shareholders, Mr. Boulton also revealed that 58,762 bushels of wheat and 31,586 barrels of flour passed over the line between March and December of 1856. The Star noted that Peterborough ladies could take the train for a mere 7s.6d, (just under two dollars) for a day's shopping and visiting in Cobourg and return in comfort the same day. Mr. Boulton's reports on the revenues accumulated each month showed the railway receiving $10 weekly per mile of track more than the Toronto and Northern Railway which was quite a successful company. On numerous occasions Boulton spiritedly defended the railway and its bridge. In The Cobourg Star he argued that:
a) proper measures had not been taken to clear the ice away from the bridge, and
b) that the piles had not been properly filled when the company took over from Zimmerman.