Since its beginnings SP has been appointed to perform unusual tasks calling for non-conventional and innovative solutions.
Giorgio Pietrangeli and Paolo Alfredo Pallavicini have always personally followed the progress of their ambitious projects, as may be seen in the photograph which shows them during the testing of the bottom outlet of the Legadadi Dam where 2 different types of dam were employed to adapt the structure to the foundations (concrete buttress and rockfill).
Construction of the Bumbuna plant was a fundamental milestone for the development of Sierra Leone.
By adopting multi-functional hydraulic tunnels, SP managed to half the construction costs without affecting the level of energy produced.
SP also had the singular task of designing the Sierra Leone banknote.
Innovative solutions in rock mechanics (see Chapter 5, Rio Grande, in "Rock Engineering, Course Notes" by Evert Hoek) or in bituminous facings (6 dams completed) together with various other engineering innovations characterize many of the firm's projects.
More recently, special “fast-track” projects have become a new challenge for SP. For instance, starting from satellite photos and Shuttle DTM, the conceptual design of Gibe III HPP was completed in less than 50 days (and this project is now being considered as an “historical” achievement for RCC dams, see Chapter 20 "Concrete Construction Engineering Hadbook"). One of the various special “fast-track” techniques comprises surface surveying from helicopters. The photograph shows Giorgio Pietrangeli during one such survey.
The founder and director of the firm, Giorgio Pietrangeli, always reminds young engineers that “l’ingegnere è una persona che si ingegna” (an engineer is a person of ingenuity) meaning that our work demands the full use our technical qualifications, culture and creativity to find solutions to the most difficult problems.
The topography is the first to be surveyed for the planning of our works. The Studio Pietrangeli has always tried to carry out these surveys using our own personnel and instrumentation, in order to maintain a direct control over our acquired data, and over its elaboration. Also in the topographic sector, SP has always been innovative and at the forefront of ideas and techniques, it’s suffice to think that as early as in 1997, for the Dankel hydroelectric project, our firm applied a topographic technique, today widely used, but at the time still at an experimental level: the aerial survey using Laser, today better known as LIDAR (Laser Imaging Detection and Ranging). A differential GPS was mounted on the body of a helicopter which was then connected to a distance meter Laser. With this technique we were able to reveal the edges of the entire Dancalia depression (Eritrea/Etiopia).
On the left of the picture you can see the designer, sitting on the protection wall , during the first opening of the bottom outlet of the dam Legadadi.
The Sierra Leone banknote with the Bumbuna dams.
Giorgio Pietrangeli while it falls from a helicopter during the first Gibe III exploration.