An interesting description of the Carthusian liturgy as it stood in pre-conciliar times:
The conventual Mass, which is always sung, is preceded by adoration of the Blessed Sacrament and the litanies of the saints.
The Carthusian liturgy differs considerably from the Roman Rite, being substantially that of Grenoble in the twelfth century with some admixture from other sources.
There are no servers at the high Mass, and the priest is attended by the deacon, who wears neither alb nor dalmatic, but the cuculla ecclesiastics and, for the Gospel only, a stole.
The subdeacon merely reads the Epistle at the lectern in the middle of the choir.
There are many other points of difference. Copes and monstrances are unknown in the charterhouse.
After the conventual Mass the priests say their private Masses, reciting Terce with the server before vesting and Sext de Beata after their thanksgiving.