PS tunnel : typical section 1955 Drawing showing the main elements of the future PS tunnel. PHOTOLAB

PS building layout 1956 Drawing of the PS ring and all buildings surrounding it. PHOTOLAB

PS building site 1956 Concrete retaining wall for the "Mount Citron" shield (built to enclose the South Hall western end). PHOTOLAB

PS building site : trial section of the ring building 1956 The earth mound covers a short, straight trial section of the PS ring structure, used to study foundations stability. PHOTOLAB

PS ring : excavation work 1955 Excavation and lean-concrete lining of a first section of the PS ring tunnel. PHOTOLAB

PS ring : foundations for "pendulum" supports 1955 The circular holes will later be drilled through to house the "pendulum" supports for the PS concrete ring foundation. PHOTOLAB

PS ring building 1955 View of the interior of the tunnel, before casting the ceiling. PHOTOLAB

PS ring : lower part of the structure 1956 The cylindrical hole will house the drilled column support for the ring structure. PHOTOLAB

PS buildings : reinforced concrete structure for shielding "bridge" pillar 1956 The PS ring traverses the region between the experimental halls South and North (buildings Nos 150 and 151) under massive bridge-shaped concrete beams. This pillar stands at the S-W end of the structure. PHOTOLAB

PS buildings : steel reinforcement for the shielding "bridge" 1956 The left-side abutment of this structure is the pillar seen in photo 392. PHOTOLAB

PS ring building 1956 The concrete ring that will support the machine will be housed in the trench occupying the lower half of the tunnel. PHOTOLAB

PS buildings : detail of the shielding "bridge" 1956 Detail of the bridge, showing the rectangular openings allowing access to the machine. PHOTOLAB

PS : South Hall under construction 1956 View looking N-W. PHOTOLAB

PS buildings : detail of shielding "bridge" 1956 Tensioning of the pre-stressing cables. PHOTOLAB

PS ring foundation on pendulum supports 1956 View showing the heavy steel bar reinforcing, prior to concrete casting. See also photo <a href="https://cds.cern.ch/record/39688">518</a>. PHOTOLAB

PS ring : pendulum supports 1956 The cylindrical shells encase the pendulum bars. See also photo <a href="https://cds.cern.ch/record/39687">516</a>. PHOTOLAB

PS ring building under construction 1956 Area near the junction Linac/Main Ring. See also photo <a href="https://cds.cern.ch/record/39702">581</a>. PHOTOLAB

PS South Hall under construction 1956 Present building 150. Inside view : in the foreground one of the overhead cranes still lying on the floor. PHOTOLAB

39693 DELETED

PS building : view of the so-called South Hall 1956 View looking East : the South Hall is present building 150. PHOTOLAB

PS South Hall : internal view during construction 1957 South Hall (present Hall 150) with all sorts of technical installations under way. PHOTOLAB

PS ring building : junction Linac to Main Ring 1957 View looking N-W. See also photo <a href="https://cds.cern.ch/record/39690">532</a>. PHOTOLAB

Inside the PS ring tunnel 1958 The ring is ready to receive its first magnet units. Note survey pillar and radius - measuring invar wire. PHOTOLAB

Mounting of the excitation windings on the PS magnet units 1958 The windings were manufactured by ACEC (Belgium) : their personnel assisted CERN for the assembling. PHOTOLAB

PS ring 1959 This sector of the PS appears nearly ready for beam tests. PHOTOLAB