The paper presents the first experimental results of studying the trunks of extensive air showers (EAS) using the high-mountain ionization calorimeter "Hadron-55" with an area of 55 m2 and a thickness of about 6 (six) proton paths before interaction. Calculations were carried out to simulate the development of EAS from protons, nuclei and hypothetical strangelets - particles of strange quark matter (SQM), probably included in the composition of primary cosmic radiation (PCR), using the CORSIKA package. The processes of passage of EAS trunks through the Hadron-55 calorimeter were played out using the Geant-4 package. The ongoing research is aimed at studying the hadronic component of EAS trunks to clarify the nature of penetrating or weakly interacting particles recorded in the Hadron-55 calorimeter.