WP3 is in charge of the design, engineering and construction of short models, prototypes and the series magnets, including spares, of the Insertion Region (IR) magnets of IR1 and IR5. This includes the Nb₃Sn triplet, separation and recombination dipoles, dipolar and higher order correctors. The mandate also concerns magnet assembly in cold masses, cold mass assembly in cryostats, the design and construction of the DCM connection cryostat, powering tests and magnetic measurements.

WP3 develops novel technologies for the Nb₃Sn triplet, with the longest Nb₃Sn magnet (7 m) and the first to be installed using a structure based on Al shells and bladder and key. It is also the first accelerator magnet to be protected via CLIQ (Coupling Loss Induced Quench), a  novel protection system invented at CERN. Furthermore, a double collaring structure to be used for the nested corrector will be a first in accelerator magnets. A second type of dipole corrector shall be based on canted cos theta design, another first for accelerator magnets at CERN.

WP3 works hand in hand with several other work packages and will actively collaborate on WP16 (HL IT String Test) and the corresponding data analysis. WP3 is also technically responsible for the interconnection of the magnets and the definition of the field model.

The WPL and deputy are charged with the coordination of the efforts within the work package and ensure in conjunction with the HL-LHC project office the progress reporting as well as the documentation and implementation of scope, cost or schedule changes.