Titanic's stern was never in danger, by that time the New York was alongside at her after part she was already going astern and the New York was under control of the tugs.
For the benefit of those not familiar with the incident, there were two steamers moored at berth 38 down by the lower Test quays near the juncture of the Test and Itchen rivers when Titanic left from Ocean Dock berth 44. The larger of the two moored steamers, the SS Oceanic, was moored against the quay while the smaller of the two, the SS New York, was moored abreast and outboard of the Oceanic. The adverse reaction leading to the incident with the SS New York was magnified because of the shallowness of the restricted waters that separated Titanic from the two moored vessels. As Titanic’s bow approached the sterns of the two vessels, a small repulsive force was set up between Titanic and the two smaller moored vessels pushing them both up against the quay. Soon the hydrodynamic force turned from one of repulsion to one of attraction as a low pressure area was set up between the advancing Titanic and the two smaller steamers. With the attractive force came an induced turning moment that acted to swing the stern of the two moored vessels outward toward the passing Titanic. As Titanic approached abreast of them, the forces became too great for the mooring lines of New York to bear, and her mooring lines suddenly snapped.
"As the bows of our ship came about level with those of the New York, there came a series of reports like those of a revolver, and on the quay side of the New York snaky coils of thick rope flung themselves high in the air and fell backwards among the crowd, which retreated in alarm to escape the flying ropes. We hoped that no one was struck by the ropes, but a sailor next to me was certain he saw a woman carried away to receive attention. And then, to our amazement the New York crept towards us, slowly and stealthily, as if drawn by some invisible force which she was powerless to withstand…On the New York there was shouting of orders, sailors running to and fro, paying out ropes and putting mats over the side where it seemed likely we should collide; the tug which had a few moments before cast off from the bows of the Titanic came up around our stern and passed to the quay side of the New York’s stern, made fast to her and started to haul her back with all the force her engines were capable of; but it did not seem that the tug made much impression on the New York. ... At first all appearance showed that the sterns of the two vessels would collide; but from the stern bridge of the Titanic an officer directing operations stopped us dead, the suction ceased, and the New York with her tug trailing behind moved obliquely down the dock, her stern gliding along the side of the Titanic some few yards away. It gave an extraordinary impression of the absolute helplessness of a big liner in the absence of any motive power to guide her.” -- L. Beesley
The tugs Neptune and Vulcan caught New York and pulled her back toward the quay while Titanic, stopped dead in her tracts by reversing her engines for a short time, was slowly drifting backward. But controlling the New York was no easy task.
"Someone sang out to me to get up and push the New York back, but such a thing was impossible. Had I got between the two ships we would almost certainly have been jammed. Instead, I turned the Vulcan around and got a wire rope on the port quarter of the New York. Unfortunately, that rope parted, but our men immediately got a second wire on board, and we got hold of the New York when she was within four feet of Titanic. Our movements were all the more trying because the broken mooring ropes from New York were lying in the water, and we stood a good chance of fouling our own propeller. Every rope on the New York snapped, the stern lines being the first to go..." – Captain Gale, tugboat Vulcan.
From photographs it could be seen that Titanic had started to drift backward after her engines were finally stopped, having been first reversed. My guess is that the anchor was dropped to keep her from drifting further backward. The entire incident caused about an hour's delay in leaving Southampton.
Ioannis, I would not say that Titanic was never in danger with New York coming as close as 4 feet before she was taken under control by the tugs.
