In the marine industry, an engine transmits power through a marine shaft, also called a propeller shaft, to a propeller drive. Almost all naval architects construct this shaft as a solid cylinder. When a crack shows up in the hub of a shaft, it is essential to take preventative measures. When solid cylinders are exposed to various mechanical stresses, cracking or fracturing is a typical failure, and most of the crack exists in single and multiple cracks. Owing to the possible interactions between fractures, they are likely to play a significant role in how the structure collapses. Consequently, this study is being conducted to address issues emerging from the interaction of multiple cracks during particular loading conditions. This paper will highlight the research conducted on various cracks interacting with parallel configurations on the cylinder's surface. Finite Element Software, AnsysTM has been employed through modelling and simulation to calculate the stress intensity factor (SIF) for various crack geometry features and separation distances under various types of loading. The dimension for length and diameter of the cylinder has been set as 200 mm and 50 mm, respectively. The values of crack depth ratio used is ranged from 0.1 to 0.4 with the increment of 0.1, while for crack aspect ratio is 0.6. The results from the SIFs are normalized for generalization to determine the interaction factor and the relationship between two cracks and a single crack.