Having failed in his attempts to penetrate the Port Arthur fortifications by direct assault, Nogi now ordered sappers to construct trenches and tunnels under the Russian forts in order to explode mines to bring down the walls. By now, Nogi had also been reinforced by additional artillery and 16,000 more troops from Japan, which partially compensated for the casualties sustained in his first assaults. However, the major new development was the arrival of the first battery of huge 11-inch (280 mm) siege howitzers, replacing those lost when the transport Hitachi Maru, loaded with a battalion of the First Reserve Regiment of the Guards, was sunk by Russian cruisers on June 15, 1904. The massive 11-inch howitzers could throw a 227-kilogram (500.4-pound) shell over 9 kilometers (5.6 miles), and Nogi at last had the firepower necessary to make a serious attempt against the Russian fortifications. The huge shells were nicknamed "roaring trains" by the Russian troops (for the sound they made just before impact), and during their period at Port Arthur over 35,000 of these shells were fired. The Krupp howitzers had originally been installed in shore batteries in forts overlooking Tokyo Bay and Osaka Bay, and had been intended for anti-ship operations.
While the Japanese set to work in the sapping campaign, General Stoessel continued to spend most of his time writing complaining letters to the Tsar about lack of cooperation from his fellow officers in the navy. The garrison in Port Arthur was starting to experience serious outbreaks of scurvy and dysentery due to the lack of fresh food.
Nogi now shifted his attention to the Temple Redoubt and the Waterworks Redoubt (also known as the Erhlung Redoubt) to the east, and to 203 Meter Hill and Namakoyama to the west. Strangely, at this time neither Nogi nor Stoessel seem to have realized the strategic importance of 203 Meter Hill: its unobstructed views of the harbor would (if taken by the Japanese) have enabled them to control the harbor and to fire on the Russian fleet sheltering there. This fact was only brought to Nogi's attention when he was visited by General Kodama Gentarō, who immediately saw that the hill was the key to the whole Russian defense.[dubious – discuss]
By mid-September the Japanese had dug over eight kilometers (5 miles) of trenches and were within 70 meters (230 feet) of the Waterworks Redoubt, which they attacked and captured on September 19, 1904. Thereafter they successfully took the Temple Redoubt, while another attacking force was sent against both Namakoyama and 203 Meter Hill. The former was taken that same day, but on 203 Meter Hill the Russian defenders cut down the dense columns of attacking troops with machine gun and cannon fire in swathes. The attack failed, and the Japanese were forced back, leaving the ground covered with their dead and wounded. The battle at 203 Meter Hill continued for several more days, with the Japanese gaining a foothold each day, only to be forced back each time by Russian counter-attacks. By the time General Nogi abandoned the attempt, he had lost over 3500 men. The Russians used the respite to begin strengthening the defenses on 203 Meter Hill yet further, while Nogi began a prolonged artillery bombardment of the town and those parts of the harbor within range of his guns.
Nogi attempted yet another mass “human wave” assault on 203 Meter Hill on October 29, 1904, which, if successful, was intended to be a present for the Meiji Emperor's birthday. However, aside from seizing some minor fortifications, the attack failed after six days of hand-to-hand combat, leaving Nogi with the deaths of an additional 124 officers and 3611 soldiers to report to his Emperor instead of a victory.
The onset of winter did little to slow the intensity of the battle. Nogi received additional reinforcements from Japan, including 18 more Krupp 11-inch (280 mm) howitzers, which were manhandled from the railway by teams of 800 soldiers along an eight-mile (13 km) long narrow gauge track that had been laid expressly for that purpose. These howitzers were added to the 450 other guns already in place. One innovation of the campaign was the centralization of the Japanese fire control, with the artillery batteries connected to the field headquarters by miles of telephone lines.
Now well aware that the Russian Baltic Fleet was on its way, the Japanese Imperial Headquarters fully understood the necessity of destroying what Russian ships were still serviceable at Port Arthur. It thus became essential that 203 Meter Hill be captured without further delay, and political pressure began to mount for Nogi’s replacement.