Slave labor would have been of little consequence to the Soviet economy without the infrastructure that enabled the movement of prisoners from the point of the labor source to the point of its utilization and eventual destruction. The Trans-Siberian Railway became the main thoroughfare that brought prisoners to intermediate points along the line from which they branched of to various places in the North. Its easternmost point, Vladivostok, was the intermediate stop for the prisoners scheduled for Kolyma. However, here the land route to the far Northeast corner of Siberia ended. The only available means to reach shores of Kolyma was by the way of the northern sea such as the Japan Sea and Okhotsk Sea. For this purpose a special fleet was organized with its base in Vladivostok.
Each of the ships of the fleet, like the Dhzurma, Sovlatvia, Dalstroy, Decabrist and many others, carried within its hold many thousands of the persecuted people, destined for extinction. All of these vessels, though of cargo design, were fitted with elaborate internal arrangements to enable the carrying of the maximum load of prisoners.
And this arrangement was of a kind that no other slave ship in the history of mankind was equipped with, not even the slave ship that carried African slaves to America.
A typical slave ship was Dhzurma. Its internal structure illustrates best how the human cargo was transported northwards within its holds. A wooden structure had been erected around the walls of its cargo holds, and comprised of four tiered bunks, with the floor serving as the fifth. Each of the bunks was divided into sections to accommodate five men in lying position. To take their places the prisoners had to slide in legs first with their heads facing the passages to avoid suffocation. If there was not enough places to accommodate prisoners, men had to use passage-way as they're put up for a sea voyage lasting six to eleven days.
The sanitary arrangements consisted of two 50-gallon barrels, called "parashas," which were emptied periodically into the sea. It was quite common for these barrels to spill over, causing the inside of the holds to smell with the odor of human waste.
An outside latrine was also available, but only few prisoners at a time were allowed to use it. Therefore the queues were always long and moved slowly. This outside arrangement was fenced with barbed wire to prevent prisoners from jumping into the sea, especially when the ship was in Japanese territorial waters.
In this crowded ship, like in the entire prison system in the Soviet Union, food was always a commodity in short supply. At the time, the whole country went hungry and slaves were at the bottom of the list when it came to allocation of food. In the ship the rations were even far below the general prison standards. The daily meal of the prisoner during the journey consisted of reduced ration of bread, a portion of sauerkraut and a bucket of fresh water for each group of fifty men. This provision of food followed the maxim practiced within the system that "men who don't work don't need food".
Ventilation of the interior of the holds was another problem for the prisoners. Fresh air was delivered through the overhead opening of the hold. 
However, even when fully opened the amount of air let in was barely sufficient to keep the prisoners away from suffocation. Then, the openings and the main door were always closed when the vessel passed the Japanese waters. For this, and other, reasons every journey took its toll in human life. Often there were additional fatalities caused by unforeseen and unexpected maritime perils.
The Dhzurma had its fair share of such tragedies. The memory of them has been preserved for posterity in books such as Robert Conquest's "Kolyma." These incidents provide a good testimony to the little value that the Soviet masters placed on human life. Here are few of the stories presented in his book.
While on one of her late fall journeys to the port of Ambartchik in the Arctic Ocean, the Dhzurma got stuck in ice, due to the early arrival of cold weather. Unable to break the ice, she remained in the frozen sea throughout the entire winter with the human cargo of twelve thousand men inside. The Soviets had no means to rescue them and they would not accept offer of the outside help, which came from an American weather station in the Arctic. In this they must have been guided by fear of exposing their slave system to the world. The entire load of men died of cold and starvation while still in her holds. Eventually the Dhzurma was freed from the ice in the spring and so was able to continue in the business for which she was designed.
On another occasion, while on the open seas, some of the common criminals, called in prison language "urkas and zhuliks," started a fire in one of the holds. The ship's command took the easiest way out. The crew shut the door and openings, and the whole shipment of human load suffocated. The fire was indeed extinguished and the ship saved for the next shipment of its human cargo.
Another disaster, mentioned in the Robert Conquest's book, related to the ship Sovlatvia which, while carrying Lithuanian prisoners and a load of dynamite, exploded at the destination.This was apparently caused by the sabotage by the prisoners. Again a small story that leaked out through the tightly sealed wall of Soviet secrecy.
A Polish source reports another sea disaster that involved the notorious Dhzurma. In the spring of 1941 the ship, while carrying a load of 8000 men (including a contingent of 3000 Poles), experienced another catastrophe that took place during a raging sea storm. In the Polish hold the center bunks collapsed burying hundreds of men under the debris of lumber and human weight. There were several death and injuries - the actual number never came to light.
The rest of the fleet on the northern route may have had similar experiences, but not all prison tales got out from the land of "white death." The secrecy of the police apparatus would not let any of it to get out from cold and frozen Kolyma.
