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weight and performance calculations for the Zeppelin LZ121 Nordstern
Zeppelin LZ121 Nordstern
role : passenger carrying airship
importance : ****
first flight : 13 June 1921 operational :
country : Germany
commander :
main operating base :
type : rigid airship class : Y
production : 1 prototype
general information :
It received the nickname Nordstern while in German service, before it was given to
France as war reparations on 13 June 1921. It was flown from Friedrichshafen to a
newly built hangar at Saint-Cyr-l'École (location : 48°48’42”N 2°4’6”E )
the Méditerranée and operated as a civilian air transport for a year making flights to
Algeria. She was transferred to the French Navy and served in the Mediterranean for
four years. She was decommissioned and broken up in August 1926.
crew : 16 passengers : 20
armament : none
engine : 4 Maybach IVa liquid-cooled 6 -cylinder inline engine 245 [hp](182.7 KW)
dimensions :
Diameter : 18.7 [m], length : 130.8 [m], gas cells :13
volume: 22500.0 [m^3]
weights :
max.take-off weight : 27500 [kg]
empty weight operational : 16000 [kg] useful load : 2000.0 [kg]
estimated tank capacity : 3582 [liter] (2625 [kg])
performance :
maximum speed : 130 [km/hr] op 2100 [m]
climbing speed : 600 [m/min]
service ceiling : 2200 [m]
range: 1900 [km]
endurance : 18.5 [hour] at cruise speed
airscrew :
four fixed pitch 2 -bladed pusher airscrews with max. efficiency :0.68 [ ]
diameter airscrew 3.20 [m]
angle of attack prop : 11.60 [ ]
fine pitch
reduction : 1.00 [ ]
airscrew revs : 1400 [r.p.m.]
pitch at Max speed 1.55 [m]
blade-tip speed at Vmax and max revs. : 235 [m/s]
calculation : *1* (dimensions)
calculated volume : 22327 [m^3]
fineness ratio (length/diameter) : 6.99 [ ]
calculation : *2* (fuel consumption)
oil consumption : 15.3 [kg/hr]
fuel consumption (cruise speed) : 168.7 [kg/hr] (230.2 [litre/hr]) at 76 [%] power
fuel consumption (long range cruise speed) : 141.9 [kg/hr]
distance flown for 1 kg fuel : 0.72 [km/kg]
calculation : *3* (weight)
weight engine(s) dry : 1600.0 [kg] = 2.19 [kg/KW]
weight transmission & gear (engines in fuselage) : 292.3 [kg]
weight 398 litre oil tank : 50.1 [kg]
oil tank filled with 5.5 litre oil : 4.9 [kg]
oil in engine 41 litre oil : 36.5 [kg]
fuel in engine 5 litre fuel : 3.7 [kg]
weight 98 litre gravity patrol tank(s) : 9.6 [kg]
weight radiator : 109.6 [kg]
weight exhaust pipes & fuel lines 110.0 [kg]
weight self-starter : 17.9 [kg]
weight cowling 29.2 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 129.1 [kg]
total weight propulsion system : 2343 [kg](8.5 [%])
***************************************************************
fuselage skeleton (aluminium gauge : 3.54 [cm]): 7061 [kg]
bracing : 373.6 [kg]
weight envelop covering (doped linen fabric 7684 [m2]) : 2459 [kg]
weight gas cell covering (doped linen fabric 4688 [m2]) : 1500 [kg]
weight gondolas : 663.9 [kg]
weight controls + indicators: 44.3 [kg]
weight seats crew : 80.0 [kg]
weight other details, lighting set, etc. : 17.1 [kg]
weight transceiver : 27 [kg]
wireless aerial : 30 [kg]
LZ121 was handed to France in 1921 as war reparation, and was renamed there as “Mediterranee”
weight passenger seats : 100.0 [kg]
weight cabin furnishing : 166.7 [kg]
weight interior + equipment + fuel lines: 335 [kg]
weight 6 fire extinguishers : 3 [kg]
weight engine mounts & firewalls : 37 [kg]
total weight fuselage : 13135 [kg](47.8 [%])
***************************************************************
weight armament : 0 [kg]
********************************************************************
weight miscell.items to high > increase weight/flight hours line 1220
weight navigation chards,flight doc.,miscell.items : 522.2 [kg]
empty weight : 16000 [kg](58.2 [%])
weight crew : 1296 [kg]
gross weight : 17296 [kg](62.9 [%])
weight cooling fluids : 150.5 [kg]
weight signal pistol with cartridges : 3.6 [kg]
*******************************************************************
calculated operational weight empty : 17450 [kg] (63.5 [%])
weight oil for 20.4 hours flying : 340.7 [kg]
weight fuel for 18.5 hours flying : 2625 [kg]
********************************************************************
Operational weight long range reconnaissance mission : 20416 [kg](74.2 [%])
at max. cruise height of : 2300 [m]
useful load : 2000 [kg]
operational weight long range passenger flight : 22416 [kg]
at max. cruise height of : 1450 [m]
weight hydrogen at s/l : 1597 [kg]
lifting capacity : 9965 [kg] typical disposable load
calculated useful lift at s/l : 25965 [kg]
published useful lift : 27500 [kg] (100.0 [%])
calculation : * 4 * (loading)
power loading (long range bomb mission) : 30.67 [kg/kW]
power loading (operational weight empty) : 23.88 [kg/kW]
power/volume : 32 [W/M^3]
total power : 730.8 [kW] at 1400 [r.p.m]
limit load : 1.5 [g] ultimate load : 2.2 [g] load factor : 1.7 [g]
design flight time : 7.40 [hours]
design cycles : 824 sorties, design hours : 6100 [hours]
drag coefficient at max. speed : 0.0024 [ ]
lifting force at s/l : 270296 [N]
lifting force at 2200 [m] : 217655 [N]
practical ceiling (operational weight) : 2200 [m] with flying weight :20597 [kg]
theoretical ceiling (skeleton crew, part hydrogen released at height) : 4250 [m] with flying weight :16690 [kg]
climb to 3000m (operational weight without bombload) : 5.00 [min]
calculation *10* (action radius & endurance)
published range : 1900 [km] (18.5 [hour] flying at 103 [km/h] cruise speed)
useful load over 1000 [km]: 2000 [kg]
production : 205.40 [tonkm/hour]
oil and fuel consumption per tonkm : 0.90 [kg]
Literature :
Zeppelin LZ 121 Nordstern - Wikipedia
confidence rating : 6.5
DISCLAIMER Above calculations are based on published data, they must be
regarded as indication not as facts.
Calculated performance and weight may not correspond with actual weights
and performances and are assumptions for which no responsibility can be taken.
Calculations are as accurate as possible, they can be fine-tuned when more data
is available, you are welcome to give suggestions and additional information
so we can improve our program. For copyright on drawings/photographs/
content please mail to below mail address
(c) B van der Zalm 13 May 2023 contact : info.aircraftinvestigation@gmail.com python 3.7.4