Italy's Weird & Wonderful Twin-Hull Flying Boats | Savoia-Marchetti S.55 & S.66

the savoya marquetti s55 was one of the weirder flying boats to enter service during the interwar period but despite its strange looks it was actually very successful and it enjoyed a large production run especially when compared to other flying boats at the time and frankly it looked really cool it was first conceived in 1923 when the reggae marina and the newly formed reggia aeronautica were looking to expand their capabilities part of this included the ability to project italian air power over the mediterranean italy's main rival in this naval theatre britain and france both had sizeable fleets and so the need arose for an amphibious aircraft capable of torpedo bombing conventional bombing and mine laying in response to this need savoya marchetti submitted the highly original design that would become the s55 the design featured twin holes that were separated almost 15 feet apart a thick three section cantilever wing with the cockpit located in the central leading edge it would be powered by two engines arranged in a tandem configuration above the wing and the tail was supported by twin booms that connected to both the wing and the twin holes for added support the twin hulls were made from wood with the frames in a mix of poplar walnut and ash while the double planking was predominantly made from cedar and plywood between these two layers of planks was a layer of cloth that was covered in a special waterproof putty and all of this combined to make an extremely seaworthy structure both waterproof and stable the twin hull arrangement also removed the need for balancing floats to be attached further out on the wings which would help with streamlining the central section of the wing was by far the most important part of the airframe not only because it connected the twin hulls but it also housed the pilot's cockpit supported the huge struts that held the twin engines in place and it also carried the aircraft's payload underneath as a result of this it was heavily reinforced with several spas being made integral to the upper structure of the hulls and extending throughout the entire span of the wing itself designed to operate with a crew of five or more probably six the s55 normally had two pilots in the central cockpit a rear gunner in each of the twin holes and a bomb aimer in the port side hull the hypothetical sixth crew member was an engineer who would maintain the engines during flight this is not mentioned in any of the sources i have found except one which happens to be the official aircraft manual that was issued by the ministry of aeronautics however the entire book is in italian and while it does not specify a total number of crew members as this was an operating and maintenance manual it does allude to a so-called engine driver station this combined with the location of the engines themselves would make sense as the engines were mounted above the wing access to them was granted by a watertight hatch that was located behind the cockpit and so it would make sense that a engineer of sorts should be able to service the engines during flight initially the s55 was designed to be powered by a pair of lorraine dietrich engines that produced 400 horsepower each the raised arrangement of these engines was popular amongst designers of flying boats at the time as it a kept the equipment as far away from sea water as possible and b completely reduced the risk of the propeller kicking up or getting caught in said seawater it did however mean that the two pilots now had a spinning propeller above their heads at a proximity that would make modern health and safety officials apply for emotional counselling but as there are no records of decapitated pilots we can assume the system was safe enough in terms of ordinance the s55 was designed to carry all of its offensive payload under the central wing section as mentioned earlier according to the official manual it could carry the following a single 800 kilogram naval torpedo or a single 800 kilogram high explosive bomb it could also carry a pair of 500 kilo bombs or four 250 kilo bombs or eight 104 kilo bombs the release of the payload was done electronically or mechanically by a control panel operated in the port side hull this also featured a modern self-contained aiming system that could be operated by day or night against moving or stationary targets the prototype model of the s55 was completed at some point in early 1925 and after initial test flights it was sent for evaluation trials these trials included testing the aircraft at its empty and its maximum loaded weights with a top speed recorded of 131 miles an hour in the air and a landing speed on water of 56 miles an hour its water handling characteristics received universally high praise and its ruggedness and stability in heavy seas vindicated the decision to go with the twin hull design as opposed to a single hull the only area in which the s55 struggled was climbing it wasn't atrocious but it wasn't exceptional either taking 16 minutes to reach an altitude of 10 000 feet and a full hour to reach its surface ceiling of 16 400 feet in the following 12 months this problem was somewhat rectified with the installation of two 500 horsepower isotopini v12s the fuel load was also increased which slightly reduced the top speed for the benefit of a significantly greater range and with these new performance figures the regia aeronautica was ready to place the first of its production orders in 1925 however the s55's fame would not come from its military career commercial variants of the s55 known as the 55c or 55p were already being built and were operating on two different commercial routes across the mediterranean however in 1925 the original prototype set 14 world records for speed altitude payload and most importantly distance this convinced savoya marchetti that their aircraft could be well suited for transatlantic flights and this would lead to the record-setting journeys that the s55 is best known for in 1927 francesco de penido an air force officer and a vocal advocate for the seaplane would embark as part of a three-man crew on what would be known as the four continents flight starting on february the 13th his s55 which had been dubbed the santa maria took off for the first leg of a journey that would eventually cover four continents and 29 000 miles most of the journey was completed without incident although unhappily the santa maria was burnt to a crisp on an artificial lake in arizona courtesy of a carelessly discarded cigarette however a replacement was sent by ship from italy and the santa maria 2 flew across the eastern united states and canada before returning to italy despite being an unarmed version of the military variant and not a dedicated commercial model the santa maria's success was a great boost for the possibilities of a transatlantic commercial service something that was of great value from both an economic and propaganda perspective to the italian government and as a result of this further ambitious flights were attempted the improved s55a would be the next to make headlines this model featured 800 horsepower esoterischini w18 engines a new top speed of 147 miles an hour and an improved range of 1200 to 2100 miles depending on its configuration 12 of these new aircraft made a 6500 mile mass flight from rome to rio de janeiro in 1930 with the flight being led by air marshal italo balboa this flight would be overshadowed three years later by the north atlantic crossing of 24 planes for the occasion of the chicago world's fair for this an aerodynamically refined model the s55x was used changes included much smoother hulls and engine cowlings fairings at the joining of all major components and new three blade or metal propellers although identical in weight to the s55a the new model can now reach a top speed of 174 miles an hour with a range of 2794 miles one s55x crashed at amsterdam on the outward journey and another at the azores on the return flight but thanks to the provision of a backup 24 s55xs still made triumphant arrivals at chicago and new york this flight more than any other single accomplishment up to this point propelled italy to a new level of prestige in the field of aviation during the 1930s besides the more spectacular long-distance flights the s55 had a long career with the reggie marina serving for more than 10 years although 13 aircraft were listed as available in 1939 the s55 had by that time reached the end of its service life and was withdrawn from service before the hostilities began as a result none of them would ever see any wartime service however this isn't quite the end of this aircraft's story as a result of the s55's early long-distance triumphs development work began on a larger model that was aimed directly at commercial travel rather than being a converted military plane this resulted in the s66 the s66 was generally similar to the s55 although it was considerably larger and was powered by three engines rather than two much to the relief of the pilots these were arranged in the pusher configuration which kept the spinning propeller blades well clear of the still open cockpit built as a 14 passenger commercial flying boat the s66 went into service in 1932 on the rome cagliari tripoli route as well as one running from rome to alexandria later on thanks to the addition of more powerful 700 horsepower engines the passenger capacity was increased to 18 and it had a top speed of 164 miles an hour not a great deal is known about the s66 however 24 are known to have been built and they were operated as civil transports from 1932 to 1939. after this at least one was impressed by the air force for asu search and rescue operations but not much is known apart from that finding source material on these planes has been especially difficult and it looks like there just isn't much left on them in terms of records however one example of the s55 still exists today which is nice as i think it's a rather good looking plane despite its weirdness it is located in brazil indeed it was used for the first crossing of the south atlantic by brazilian pilots but its fate has been shrouded in doubt as the tam museum faced financial problems in 2016. however it now looks like after a stint in temporary storage it will be going into a brand new hangar in the near future for the public to be able to see again savoy and marchetti weren't the only ones making weird and wonderful flying boats in the interwar period in fact there are some truly adventurous examples out there that i plan to cover but those of course are videos for another day as always thank you all so much for watching and i'll catch you all next time goodbye [Music] you

Channel: Rex's Hangar

Views: 88,183

Keywords: savoia marchetti s55, savoia marchetti, regia aeronautica, italian air force, regia marina, savoia marchetti 266, twin hull flying boat, flying boat, ww2 documentary, interwar period, seaplane, aviation history, aircraft design, aircraft documentary, Italy's Beautiful Twin-Hulled Flying Boats, rex's hangar, savoia-marchetti, savoia-marchetti s.55, italian aviation, flight, aeroplane, military aircraft, civil aircraft, weird aircraft

Id: IWV0nJQf9eY

Length: 12min 35sec (755 seconds)

Published: Sat Mar 26 2022

Reddit Comments

[u/Jimmy_the_Heater]

Rex's Hangar does such a wonderful job on these vids. Well worth the watch.