Engineering Excellence
Working to the very highest standards, Hercules provide a full overhaul and repair service for Rotol propellers in our dedicated repair facility. We have the added advantage of full in-house spare parts manufacture.
We offer a collection and delivery service within the UK and through Europe. We can also arrange international shipping with on-site assembly.
ROTOL complete service
- Full ROTOL propeller overhaul service
- Complete ROTOL propeller manufacture
- In House ROTOL hub and parts manufacture
- Highly authentic Spitfire propeller blades for 3, 4 and 5 blade propellers
- Precise balancing
- Correct and authentic 1940’s blade markings
- Collection and delivery service
- UK CAA approved for Hoffmann Spitfire blade overhaul
- Full OEM original drawing and document archive
Full UK-CAA approved in house manufacture and overhaul facility for ROTOL variable pitch propellers
ROTOL hub and parts manufacture
Hercules are fortunate to be supported by Dowty Propellers (formally Rotol) who provide us with technical support and access to their vast archive of component drawings and specifications.
Our UK CAA design and production approvals along with our in-house precision machining capabilities enables us to produce the full inventory of spare parts for Rotol propellers, identical to the originals.
Manufacturing and overhaul of Spitfire propellers at Hercules
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ROTOL History
Pictured above King George VI and Queen Elizabeth inspecting hydulignum at the Hordern-Richmond factory during WWII - as still used today by Hercules
Correct and authentic 1940’s blade markings
We finish our Spitfire blades with the correct and authentic markings from original Rotol design documentation.
Reproduction ROTOL propeller blades
Hercules Propellers are Rotol Spitfire propeller hub and blade manufacturing specialists. The blades we manufacture are constructed according to the original Rotol drawings. All of our parts are British made, within 10 miles of the original Rotol factory.
Hercules produce immensely authentic blades which are are constructed from Hydulignum, the original material used by Rotol. Our blades are true to the WW2 construction design and aerodynamics. The steel root adaptors are threaded onto the blade roots, just how ROTOL intended.
Hercules Spitfire propeller blades are approved by the UK-CAA and are included in the Dowty Rotol Service Bulletin as an original manufacturer’s approved alternative to the originals. During our product development, extensive material strength testing was carried out and a full instrument flight test plan completed. It has been noted by all pilots who have flown Hercules’ Spitfire blades how smoothly they run.
Hercules Spitfire propeller blades have no restriction on RPM or horsepower.
Hydulignum
Our immensely authentic blades are constructed from Hydulignum, the original material used by ROTOL and are true to the WW2 construction design and aerodynamics.
Developed for propeller manufacture by Hordern-Richmond in the 1930's, Hydulignum consists of very thin veneers of beech wood impregnated with phenolic resin before being compressed and densified in a heated press to create an original composite type material with very high tensile strength for its weight. Our hydulignum is produced in accordance with the original Rotol specifications and is extensively strength tested by us.
Precise balancing
During manufacture, our Spitfire blades are constantly checked against a master weight to ensure that the set are precisely matched. This makes for an extremely smooth running propeller - something that Hercules blades have become renowned for.
Hercules blades are also aerodynamically balanced in accordance with the Rotol design data. Because our blades are so accurately made, no setting correction angle is needed. Hercules blades are always set to 'NORMAL' meaning that no compensation is needed for manufacturing inaccuracies. This adds to the running smoothness.
ROTOL overhaul shop
Hercules have invested heavily in knowledge, tooling, equipment, training and approvals to create a world-class overhaul devision.
Backed up by extensive documentation, drawings and close ties with Dowty Propellers (formally Rotol) Hercules provide the highest standards of aerospace engineering.
Hercules have an in-house parts re-plating facility for enhancing quality and minimising overhaul turnaround times.
ROTOL hub overhaul
3-blade Rotol (Spitfire V and Hurricane) blade and bearing housing assembly jig
Drive centre removal for Service Bulletin compliance using a hydraulic press. No requirement to re-ream taper bolt holes
Brand new manufactured Spitfire V hub shell
Overhauled Spitfire IX hub ready for assembly
Assembled Spitfire IX propeller showing Hercules in-house plating
Overhauled Spitfire IX propeller ready for delivery
Hoffmann Blades
Hercules have a UK CAA Airworthiness Approval Note (AAN) that enables us to legally overhaul Spitfire and Hurricane blades produced by Hoffmann. Our in-depth procedure includes NDT of the blade adaptors and static resonance tests to asses the blade's structural integrity. Our approval for Hoffmann blades includes provision for minor repairs and complete paint re-finishing.
ROTOL History
ROTOL History
HERCULES ARE ROTOL SPECIALISTS
