Port
Left.
Pressure Airship
An airship that maintains its shape by maintaining the gas in the envelope at a slightly higher pressure than that of the surrounding atmosphere. Ballonets that contained air were fitted inside the envelope. They were filled as the lifting gas contracted, and emptied as the lifting gas expanded. This maintained a constant volume at all times. Non rigid and semi-rigid airships are both types of pressure airships.
Pressure Height
The height at which the lifting gas in an airship fills 100 percent of the envelope. If the airship climbs above pressure height, it has to valve off gas to avoid the envelope splitting open.
Rip Panel
Part of the envelope of a pressure airship or balloon that will open when a rip cord is pulled, and lets the gas out with a rush. When a balloon or airship is landed in a strong, gusty wind the envelope acts like a sail is and is blown around until the gas is vented. The quicker the gas is let out the better, hence the rip panel.
Roll
The motion of an aircraft around its longitudinal axis. Aeroplanes roll when the ailerons are used. Airships have no control to roll them but roll slightly when the rudder is used and in turbulence they pitch, yaw, and roll.
Rudder
Control surface hinged to the vertical fin and providing control in yaw (the nose moves left or right).
Seaplane
An aeroplane designed to take off and land from water. The main types were floatplanes and flying boats.
Semi-Rigid Airship
A pressure airship with a keel along the bottom of the envelope. The keel stiffened the envelope, simplifying the maintenance of shape and providing an attachment point for some of the gondolas.
Sponsons
Wing like stabilisers mounted on the hulls of some flying boats and used to keep them upright when afloat. The Dornier Wal flying boats were equipped with sponsons.
Starboard
Right.
Static Lift
The displacement of air by a lighter than air lifting gas (e.g. hydrogen) produces static lift for balloons and airships.
Step
A seaplane is said to be on the step when the hull lifts partly out of the water during the take-off run and can then accelerate to flying speed.
Sun Compass
An aid to air navigation. Used to steer a steady heading when the magnetic compasses were unsteady or unreliable due to the close proximity of the magnetic north pole. They were set before take-off, and the longitude and time had to be known accurately, and the sun had to be clearly visible. The 1925 flight used clockwork drive Goerz sun compasses.
Trail Rope
A balloon was normally equipped with a trail rope which was rolled in a ball and could be dropped with the one end attached to the balloons load ring and used to maintain height automatically while flying low over a smooth surface or water or to cushion the final descent while landing.
Variometer
An instrument which shows whether an aircraft is climbing or descending and the rate at which it is. Usually calibrated in feet per minute.
Wing
The large fixed surface of aerofoil section which provides an aeroplane with its lift and a mounting for the ailerons. The Dornier Wal was a monoplane (single wing), but the wing was said to be made up of the port (left) and starboard (right) wings.
Wing Tips
The outer one third of the port and starboard wings.
Yaw
The motion of an aircraft around its vertical axis damped by its fin or fins and controlled by its rudder.
Appendix Two
Dornier Wal (Whale) Flying Boat
GENERAL DESCRIPTION: Twin engine, monoplane flying boat of all metal construction.
HISTORY: The Wal was designed in Germany by Claudius Dornier (1884–1969) but could not be manufactured there because of the Treaty of Versailles of 1919 which ended World War I and imposed a moratorium on the manufacture of aircraft by Germany. The prototype Wal flew for the first time on November 6, 1922. Both the Amundsen-Ellsworth aircrafts were manufactured under license in Italy by Societa di Costruzioni Meccaniche di Pisa of Marina di Pisa. SCMP manufactured both civil and military versions. The expedition’s aircraft were military versions, without armament, and with modifications including rear gunner’s position faired over, extra flight and navigational instruments, and extra fuel tankage.
Constructor’s number 19 was completed on January 30, 1925, and was test flown on February 5, 1925. It received the Norwegian civilian registration N24. It was abandoned on the pack ice on June 14, 1925, in position 87° 44’ N & 10° 20’ W.
Constructor’s number 20 was completed on February 19, 1925. and test flown on February 21, 1925. It received the Norwegian civil registration N25. After the 1925 expedition it was bought by Frank Courtney, re-registered G-EBQO, and re-engined with 450 hp Napier lions. After two unsuccessful attempts to fly the Atlantic it was re-engined again this time with 600 hp BMW Vs. and sold to the German School of Civil Flying (DVS) at Sylt. It was used for a flight across the North Atlantic in 1930 by Wolfgang von Gronau. The German registration was D-1422. In 1932, it was donated to the Deutsches Museum and displayed until it was destroyed in an allied air raid in 1944.
ENGINES: Two water-cooled Rolls Royce Eagle IXs, each of 360 hp. Mounted in tandem on the center section of the wing, with the forward driving a tractor propeller, and the aft driving a pusher propeller. The engines shared a single radiator mounted between and above the engines.
PROPELLERS: Two four-bladed, fixed-pitched, wooden propellers, one a tractor and one a pusher.
DIMENSIONS: Span 22.5 m, length 17.25 m, height 5.2 m, wing area 96 m2.
WEIGHTS: empty 3,560 kg, normal maximum take-off weight 5,700 kg, take-off weight for polar flight 6,660 kg.
PERFORMANCE: Maximum speed 180 kmh (98 kt), cruising speed 150 kmh (81 kt.), rate of climb 33 min. to 3,000 m (9,842 ft.), (298 ft. per min.), range (with overload fuel and no reserves or allowance for wind) about 2,400 km (1.296 nm). Endurance at 150 kmh about 16 hours.
• The only surviving Wal is said to be Plus Ultra which is in the Museo del Transporte in Lujan, Argentina. The Plus Ultra was flown from Spain to Argentina by Ramon Franco and his crew in 1926.
• A full size replica of Amundsen’s Wal N25 was unveiled at the Dornier Museum, Friedrichshafen, Germany on July 25, 2012.
Appendix Three
Airship Norge
GENERAL DESCRIPTION: N class semi-rigid airship.
HISTORY: Designed by Umberto Nobile for the Italian Navy. It made its first flight in 1924. Purchased by a Norwegian organisation in 1926 and modified for the flight from Italy to Alaska. The Norwegians took delivery at Rome on March 29, 1926. From April 10 to May 7, 1926, it was flown from Rome to Kings Bay in stages: Rome–Pulham (England)–Oslo (Norway)–Leningrad (Soviet Union)–Vadsø (Norway)–Kings Bay (Spitsbergen) in 100 hours flight time. This flight positioned the airship at Kings Bay for the great trans-polar flight. The non-stop flight from Kings Bay to Teller (near Nome, Alaska) by way of the North Pole took place from May 11–14, 1926, and the ship was in the air for 70 hours. The airship was dismantled at the landing site, and never flew again.
Flight Log:
April 10–May 14, 1926
Rome-Pulham
32 hrs.
Pulham-Oslo
14 hrs.
Oslo-Leningrad
17 hrs.
Leningrad-Vadsø
21 hrs.
Vadsø-Kings Bay
16 hrs.
Kings Bay-Teller
70 hrs. 40 min.
Total:
170 hrs. 40 min.
Technical Information:
Volume
18,500 m3
Length
106 m
Diameter
19.47 m
Empty weight
13,000 kg
Useful lift
8,274 kg
Maximum speed
61 kt.
Cruising speed
43 kt.
Endurance (at 43 kt.)
75 hrs.
Range
3,225 nm
Engines: 3 x Maybach Mb IVa six-cylinder, water-cooled, 250 hp (each)
Crew and Passengers (Polar Flight) 16
From Pole to Pole Page 23