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Mooring Mast Technical Information
Testing, Construction and Designs

The design concept for mooring airships without the need for a ground crew came from the original concept of the "three wire system". Experiments were carried out by the ability to moor airships from three wires from the bow of the ship, then the ship "flown"with the wires taught. This proved that airships need not be housed in the hangers, of which the Germans had proved was the time when the ships were most vaunrable.

The first high mast was developed in Pulham where a mast erected and an airship was able to dock, the crew could alight the ship, and also be refuelled and ballasted at the same time. The advantages of a high mast was that an airship could be moored both day and night, along with the fact that a craft could take up moorings in windspeeds of up to 35 knots.

The first mast was a lattice mast constructed by Vickers, with the intention that it should be erected at Barrow-in-Furness, but in May 1918, the decision was made to errect it at Pulham. The Vickers mast was a comparatively short tower, 120ft high, was capped by a mooring attachment which allowed the moored craft to swing through a full 360 degrees so that it would face the wind at all times. A fundamental advantage of the new system was that only a dozen or so men were needed to secure the craft, instead of the large ground handling party required earlier. This was of particular importance during a period of austerity and financial restrictions.

Vickers Prototype Mast

As the new mast was deemed a prototype, it had no lift to enable the ship's crew or passengers to reach the top in comfort. Insread they had to climb the many steps up the outside of the tower to reach the rotating cap at the top. Entry to the ship was gained by means of a circular platform encircling the cap, from which one clambered up through a hatch in the nose of the ship

HMA No.24, the second ship of the 23 Class, was flown from Howden to Pulham on 31st May, 1918, with the intention that she would be used for mast mooring trials, but is was not until March 1919, that the mast was setup at Pulham. No. 24 was fittted with a modified nose cone, a bow coupling which and additional ballast tanks, and her midship gondola was removed before trials could begin.

The No.24 was moored at the mast for the first time on 11th June, remaining on the mast until 30th June. The ship was taken from the mast for inspection and minor modifications, but was back on the mast from 1st September to 15th October, and again from 7th November until mid December. In these experiments the mooring cable was attached to the mast whist the ship was on the gound, and no "yaw guys" were used to steady the ships nose, as she approached the masthead. Two men remained on duty in the control car and one below during her sojourn on the mast, so that water ballast could be taken aboard by hose if she became light, and began to ride up. Gas could be fed in if she became to heavy for a discharge of ballast to be beneficial. During the ships total of sixty-two days on the mast, in all weathers the ship coped with wind speeds of 45mph without trouble.

Whilst at Pulham, No.24 tested a system involving the use of ropes to guide the ship down; this was not found to be satisfactory, though it did lead to the development of a more functional system some time later. H.M.A No.24 was deleted before the end of the year, and it was left to the R.33 and R.36 to carry on the mooring trials at Pulham.

The revolving masthead was later fitted with an attachment designed at Cardington. Named the Bedford-Pulham mooring attachment, it comprised an elaborate arrangement of cables intended to facilitate the linking of an airship to the tower. One ran from a winch at the base of the tower, through an attachment at the top and then out at a downward angle to another attachment set in a large concrete square on the airfield some distance from the tower. At this end was a quick-coupling device.

Airships equipped to user this morring arrangement carried a similar cable and coupling attachment in their bow section. To moor, the airship slowly approached the concrete square at a low altitude and in line with the cable running up to the top of the tower. The airships's cable and coupling attachment was lowered and a member of the gound crew, positioned adjacent to the concrete square and lower attachment, prepared to receive the cable. Great caution had to be exercised at this juncture as the airships passage through the air had generated considerable static electricity, which would earth itself as soon as the cable was close to the ground. To save himself from a almost fatal shock, the ground crew member had to ensure that hte cable had touched the ground before he attempted to retrieve it.

When all was safe, the airships cable was attached to the ground cable and the cable would be gradually wound up towards the top of the tower. Eventually the nose of the airship reached the mooring attachement on the tower to and fastened securely to the tower. As the top of the tower revolved, it allowed the airship to ride into the wind, or weathercock, in airship terminology. Advanages of this system was that a craft could thake up moorings in wind speeds up to 35 knots.

The new mast was used a great deal and over serveral months some fifty successful moorings were made by the R.33 under the supervision of Captain Williams, this involved some 171 hours of flying. On surprising fact which emerged from these trials was that the craft could be brought up to the mast and attached in very bad weather conditions. One report stated that the R.33 was successfully moored when the wind was gusting at 80mph. The R.33's stint on the Pulham mast proved that the design was sound and efficient, and that a great step forward had been taken in ground handling of airships. Many local residents recall the impressive sight of the R.33 siding the mast at night, with floodlights shining on her silver-coated hull; the lights on board gave the impression of an ociean linder lying in dock.

During her many days on the mast, the R.33 proved neither rain nor dry snow posed a problem, but following the destruction of R.26, it was recognised that wet snow certainly did. Captain F.M Thomas at Pulham devised a snow clearing gear which consisted of an endless wire atop the ship between frames 7 and 34, which dragged lenghts of 2.5 inch hemp rope fore and aft along the ships cover, to clear the snow which had accumilated on the top of the hull.

On 3rd June, 1921, a heavy rain squall forced the tail of the ship to the ground, despite a release of ballast. It was thought to be the dynamic pressure of the raindrops rather than the their actual weight that did this. Fortunately, the tail fin was submerged in a pond, and on that occassion, the airship escaped damage.

The Pulham mast was used for a number of years by many of the ships stationed there. All British rigid airships were fitted with bow mooring gear and crew/ passenger access. Later development of the mast lead to a higher mast of some 200ft, which also contained a lift for easier access for crews, passengers and goods.

The nose entrance design was incorporated in to the R33, R36 as well as the standard moring design of the R100 and R101. With the later loss of the R101, the Government proposed the use of or leasing of the masts and sheds to the Zeppelin company. It was noted that the Graf Zeppelin and later Hindengburg designs would have had to be altered to incorporate the access via the nose of the ship.

Mast Specifications
Height
202ft
Diameter at base
70ft
View the mast in operation - click on the movie clip above
Photo Gallery
R33 on the first high mast design for an airship
Close up of the nose of the R.33 attached to the Vickers Mooring mast at Pulham, and crew entering the ship 24th March 1921.. The 360 degree platform can be seen, and small nose hatch for the crew.
A view from the R33 towards the Pulham Mast
 
   
 
 
The Mast plans for the Standard High Mast
A plan of the masthead and entry to the Airship
The mooring schematic for the proposal of mooring large airships against high masts.

Artist impression showing the masthead and connection machinery in place.

   
           

Mooring an Airship

The following is a description of how the mooring of an airship would be undertaken, this was from an article written in the Times from August 1920 when a ship would be moored to the Pulham mast, which was a smaller mast with no elevator



“Every time an airship sets out on a voyage an army of men has to be employed to help get her away, with the aid of guide ropes. The voyage over, the berthing of the vessel again involves guide-rope control from the ground. Before long, however, these primitive methods may be replaced.

The problem has been tackled by Messrs Vickers, Limited, at their Barrow Works. Steel towers are being constructed there from which it will be possible to supply airships moored to them with fuel, water, gas, and goods; and crew and passengers also will be able to go aboard from the towers.

The completed mooring tower will be about 150ft high, built of steel lattice-work and furnished with a revolving head. To this the airship will be closely moored, bow on, and floating clear of the ground the vessel will be able to swing round with the direction of the wind, the necessary protection from which is provided by the stream-line shape of the body. A winch and cable will bring the airship to the tower-head, and a lift working inside the tower will carry crew and passengers, fuel, stores, cargo, and so forth, to the airship.

At the top of the tower a small compartment will serve as an ante-room to the airship, connected by a flexible enclosed gangway. An airship making for the tower will send out a wireless message announcing her intention. From the tower head a wire cable will be dropped to the ground and there picked up by a man who will enter a small car and drive away some 300 yards. A second cable, weighted with sandbags, will be dropped from the airship when a ground signal has indicated the point at which it will be picked up, and the two cables will be coupled.

The airship will then be hauled in, assisting where necessary with her own power, and when she has been moored it will be possible to uncouple the cables and re-wind them. The airship will be released automatically from the mooring tower by a mechanism controlled by one man, so that from first to last, apart from those on board, not more than three men will be needed to bring a dirigible to port and send her out again. Some of these towers will be completed shortly and supplied to aerodromes without delay. At the foot of the tower waiting-rooms will be built, which in the future might be developed into hotels.”

Construction

The huge airship mast was constructed for the civil programme in 1926, built by the Cleveland Bridge and Engineering Company under the direction of Major General Sir William Liddell, Director of Works and and Buildings at the Air Ministry. The Cardington Mast was completed in 1926. The Cardington and Ismalia masts were both up to the level of the searchlight gallery to the tower were an open work structure made up of eight main legs set in concrete bases and cross braced on all eight faces to horizontal frames arranged at intervals of 28ft 4 inches.

From the searchlight gallery upwards the surmounting tapered circular turret was framed in steel, endoused with corrugated sheeting and lt by sixteen windows. The top platform, at a height of 170ft, from wich the passengers embarked and disembarked in to the airships, was 40 ft in diameter and encircled by a heavy parapet. The top rail of this parapet formed a track on whic a gangway, left down from the ship, ran on wheels to give freedom for the airship to move around the top of the tower as it swung in the wind.

A lift shaft, 9ft 6inches, ran up the centre of the tower in a separate block, with a stairway around the outside. The electric passenger lift, with capacity for 12 persons at a time, ascended to a height of 156ft from the ground at which level there was a steel platform with stairs up the remaining 14 ft to the passenger platform.

 
   
The very first stages of the Cardington Mast construction early 1924
The basde of the mast under construction at Cardington,1924. Part of the mooring head machinery is about to be winched up the central stairwell.
The mast nearing completion, here without the mast head housing
The mast almost completed and winch buildings being added.
   
         
 
 
The mast head constructed showing the nose docking arm fully extended
Inside the mast head, showing the suspension mechanism for the docking arm and the extendible arm retracted. It was maneouvered on the pulleys attached to it's lower end.
In this photo of a visit by MP's, the mast head controls can be clearly seen.
     
The Missing Masthead

Babcock and Wilcox Ltd were the main contractors for the mast head machinery. They had already produced the mooring machinery for the Cardington, Ismaila and Karachi masts . The second sets of orders were already being placed and the Montreal and South Africa masts were ordered at the same time and it is noted that Babcock and Wilcox gave a 2% discount on the mast head prices due the "bulk" order. The Montreal mast was completed first as it was the Montreal trip was which deemed to be one of the primary trips for the demonstration flights of the new airships. This was delivered to Montreal in August 1928 and so it is expected that, at that time, the South African mast heard would have been completed after this date, maybe early 1929.

Whatever happened to the South African masthead was unknown but however years later a comment was made to a member of the AHT stating that when posted in Aden during the second world war, a "airship masthead was seen in storage". How true this is, we cannot confirm, however it would tie in with the fact that the Canadian mast had to be constructed first as it was always agreed as part of the "demonstration" flights of the 1924 Airship Programme. Therefore if the first masthead was constructed and delivered in 1928 then the second mast head would have been constructed and also forwarded for onward delivery to South Africa. Aden is a key port for trade on the west coast of Africa. On the 1926 proposal map, both Cape Town and Durban are noted, however on a later edition map, presumed to be end of 1930 shows both Durban and Cape Town to be proposed Airship bases with masts and sheds facilities.
 
Testing the Mast
Once the mast had been completed, the testing of the design was needed. A strain test to 30 tons was ordered and undertaken by a pulley system to test the strength of the mast tower and mooring machinery
The wires were connected from the top of the mast to a steam winch and pulley system on the ground
The team assembled on the ground
The pulley connection to the steam winch.
The connection at the top of the mast, and with no health and safety, the technician is checking the loading guages at the top of the mast.
A member of the team measuring the tension on the wire

 

Mast Variations
This later design became the template for all masts constructed for the Imperial Airship scheme and masts were constructed of the type in Cardington, Ismailia in Egypt, Montreal in Canada and Karachi in India, each one adding to the success of the desing. Interestingly each mast design was altered for example buildings added in to the base of the mast in Montreal and Karachi designs.

 
 
The Ismalia mast was a virtual copy of the Cardington mast layout
The Karachi mast had buildings incorporated in to the base of the mast, but an exposed lift shaft
The Montreal mast had buildings in a classical "Regency" influenced design at the base and enclosed lift shaft. The mast top was painted orange and silver to make spotting the mooring easier to the pilots
The R100 was the only airship to use the Monreal mast.
   
Mooring Masts In Use

The success of the earlier mooring trials with the R 33, meant that the new high mast and mooring gear would be used for future airships. The R33, R34, R36 were fitted with a boarding "hatch" in the nose, whilst later ships incorporated the design during construction and the R38, R100, and R101 were all fitted with a retractable doorway for easier access. This meant that the masts could be used by multiple ships, and became a standard feature in British airship design.
   
The first ship to use the newly completed mast was the R 33, which can be seen here moored to the mast.
The R101 soon followed in 1929
The R100 also moored to the Cardington mast, here showing her original configuration just after her first flight from Howden construction facility, to Cardington.
The close up on the nose and the access to the ship.
Close up of the mast head. Also can be seen are the searchlight emplacements and the gas hoses for topping up the gas in the ship via the nose.

 

Decomissioning of the Mast
   
   
 
A remaining strut of the Cardington Mooring mast - part of the AHT collection
     

The Cardington mast remained a prominent feature of the local area some 13 years after the last airship docked to it, and was decomissioned in 1943 and sold for scrap. The original concrete base still remains to this day, along with the power house. As late as 1983 the pile of clapboard buildings could still be seen, which had once performed the historic role of Customs Office for passengers travelling abroad by airship. The Customs House was only used on three occasions, for the R100's out and return flight, and the R101's departure to Karachi, in 1930.

As part of the AHT Collection and Archive, a girder piece was presented to the Trust by Mr John Benson, who as a child from the age of 2, lived in one of the wooden buildings which was designed as originally been provided as accommodation for the Airship crew. He live on the mooring mast site for 11 years with is mother and father. His father was employed as a cowman by Mr Alex Simpson, farmer at Manor Farm, Cotten End, on which land the mast site stood, who offered him and his family the use of the buildings. Mr Benson decribes life on the site as interesting, as they had the luxury of a flushing toilet, coke boiler and bathroom, the power supply had been disconnected. He remebers the building being backing hot in the summer, and freezing in the hard winters of the late 40's and 50's.

The mast had been demolished before he moved in, however as a connection to the past, the address was "The Bungalow, Mast Road, Cotton End". One of the larger buildings which is still standing on the site, was spruced up and decorated by the Cotton End villagers in June 1953, and used as a venue for a tea party to celebrate the Coronation, as that time there was no village hall. An electric cable was run across the fields from the farm so that the Coronation could be watched on television.

At that times there were many items of the removed mast laying around the site, when the family evenutally moved from the site, they took this girder as a souvenir.

The girder was a bracing member of one of two in the form of a cross, and they can be clearly seen in photo's of the mast. The girder is exactly 6ft in length, two inches wide, and has a stamp of JC&S Ltd.clearly marked twice on the side, with three fastening holes drilled in to it. To our knowledge, apart from the wooden boxes made out of the the lift carriage for sale to benefit the Red Cross, this is the only other surviving peice of the mooring mast.

 

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