A new class of Bianchi type I viscous-fluid cosmological models with a variable cosmological constant are investigated in which the expansion is considered only in two directions, i.e. one of the Hubble parameter (H1 = A4/A) is zero. We have considered four cases: (i) coefficients of bulk (ξ) and shear (η) viscosity are taken as constant, (ii) ξ and η are considered to be inversely dependent on time, (iii) Λ is taken as inverse square of t and (iv) ξ and η are considered as proportional to scale of expansion in the model. The cosmological constant Λ is found to be positive and is a decreasing function of time which is supported by results from recent supernovae Ia observations. Some physical and geometric properties of the models are also discussed.Istražujemo novu vrstu kozmoloških modela viskoznog tekućeg svemira Bianchijevog tipa I s promjenljivom kozmološkom konstantom, u kojima se širenje razmatra samo u dva smjera, tj., jedan od Hubbleovih parametara, H1 = A4/A, jednak je nula. Razmatramo četiri slučaja: (i) volumni i viskozno-smični koeficijenti, (ξ) i (η), su stalni, (ii) (ξ) i (η) su inverzno razmjerni vremenu, (iii) Λ je razmjeran inverznom kvadratu vremena i (iv) ξ i η razmjerni su ljestvici širenja svemira u modelu. Nalazimo da je kozmološka konstanta pozitivna i opadajuća funkcija vremena, što je u skladu s nedavnim ishodima opažanja supernova Ia. Raspravljaju se također neka fizikalna i geometrijska svojstva tih modela
