Hugh Morrison was an apprentice at John Browns working throughout the lifetime of the QE2 and recounts the details of the launch on September 20, 1967.

Like all vessels, the ship would have three key points during its building: the laying of the keel, the launch and the final sail away from the shipyard.

The launch of the QE2 was by far the most spectacular of the three events and it attracted large crowds to witness the it.

Those people who were in the shipyard, employees and invited guests had been issued with tickets allocating the areas which they should stand. Like all staff members I was issued with four tickets and I attended the launch with my father, my uncle and my best friend.

Other people crowded the field on the opposite side of the river, hoping not to get wet if the launch the up a wave. The method of launching the QE2 was the basically the same as all vessels, it was just that the QE2 was bigger than average and the largest since the launch of the Queen Elizabeth in 1938.

The launch is a spectacular event but unfortunately most people do not understand what the various phases of the launch actually are, especially as it all happens so quickly - less than one minute. Nor do they understand the potential dangers which occur and the forces which are exerted on the ship's hull.

The date and time of the launch were decided far in advance to coincide with the time and height of the high tide.

For a week prior to the launch the tide heights and times were checked against the predictions. In performing the calculations for the launch, the majority of which were performed by hand using slide rules and mechanical calculators, the margins of toleration in the tidal level had to be calculated.

If on the day the tide was above or below those limits, the launch would have to be abandoned. Fortunately this was not the case.

The stability of the ship also had to be checked to make sure it did not capsize after launch - something which had happened previously in  Clydeside and other yards.

In the few days prior to the launch the hull was completed and the first few decks of the superstructure were in place. The hull was supported by multiple wooden props, much as may ships all the way back to the Lusitania and beyond, had been supported.

The building ways - the two long strips of wooden structure upon which the keel had been laid - had been gradually been replaced by the launch ways.

The lower part of the launch ways are fixed and the upper launch ways, upon which the ship sat, was mounted on a layer of wax and grease which would eventually let the ship slide into the water.

Where the shape of the ship at the bow and stern did not contact with the launch ways, large frameworks, called poppets, were fitted to make sure the ship was as evenly supported, along the whole length, as much as possible.

As the launch moment approached and when it was confirmed that the launch would go ahead the props were systematically knocked away by the shipwrights until the ship was left sitting only on the launch ways.

All that was holding the ship in position then and stopping it from sliding down the ways were six so-called triggers. These were large mechanical devices (originally made for the Queen Mary): when the launch button was pressed an electrical/hydraulic system release each trigger simultaneously leaving the vessel free to begin its transit into the water.

A tarmac path had been laid from the launch stand along and under the vessel to allow the Queen to go and see a trigger and understand what happened when she pressed the button. The trigger was nicely painted to make it look good for the guest.

On her return to the launch stand the Queen duly gave her brief launch speech and pushed the button.

As is well documented, nothing happened and the ship showed no sign of  movement. There are photographs and films of the bowler-hatted Mr George H Parker, the shipbuilding director, giving the top end of the ways a push to help the ship on its way. After a few somewhat embarrassing minutes, with breaths being held all round, the ship eventually started to slowly move.

The reason for the delay was that one of the triggers had not released properly. The reasons for this have never been properly explained officially - there is at least one rather amusing reason, but it was denied by the ship management. The ship being held in place by just one trigger was potentially a very dangerous situation. However, whatever the actual reason, the problem was certainly solved by a shipwright using his best tool, his sledgehammer, which helped release the trigger.

The angle at which the launch ways had been built had been decided very early in the design process based on estimates of the ship weight, etc. The angle of the ways would govern how quickly the vessel moved down the ways.

After the vessel started to move it gained speed. Very quickly the aft poppet and the stern started to enter the water, the stern becoming increasingly deeper into the water. The position of the stern in the water then reached a point where the water being displaced caused the stern to become buoyant. This is the point where the stern rose - that can be easily seen on any film of the event.

That point where the stern rises is one of the most critical points of the launch.

The ship is then only supported along its length by the portion of the hull which is in the water and the forward poppet, meaning that the whole ship is tending to bend.

The forward poppet is fitted with areas of wood which crush under the load and help the distribution of the weight. Because the vessel is moving, such danger points pass very quickly and whole ship eventually gently dropped off the end of the launch way, giving a little bow as it bobs into the river. 

The vessel is now launched and fully afloat.

It was however still moving and had to be brought to a stop.

Fortunately the Clydebank yard was purposely built opposite the confluence of the River Cart to allow some leeway during launch. The ship was slowed down and stopped using drag chains - 12 great piles of chains, six on each side, each weighing several hundred tonnes.

The drag chains were fixed to the hull so as to come into action progressively.

The theory was that the first two sets of chains would slow down and stop the vessel and that the third set was a back-up.

I remember the chief naval architect at John Browns asking the engineer who led the launch calculations if he was confident enough to sit on top of one of the last chain piles.

As it happened, the third chain piles did not move.

The chains lines were then detached, the tug lines attached and the ship towed it into the fitting out basin into the position where so many of its predecessors had sat, for its completion into the vessel that would remain in operation for more than 40 years.