Non-self-propelled icebreaking and ice cleaning attachments

Ship type:

Purpose:

To make it possible to pilot river vessels in ice conditions using the existing tug fleet of Central Engineering Design Bureau-Engineering Center of Shipbuilding, projects of non-self-propelled icebreaking and ice-clearing attachments were developed, both using a rocking installation (projects 1713 and 1749), and easier-to-build and operate icebreaking and ice-clearing attachments without rocking installation (projects 2158 and 2211).

Class of the register:

Year of construction of the lead ship:

Characteristic	Project numbers
	1713	1749	2158	2211
Class of the Russian River Register	“E O” (icebreaker)	“E O” (icebreaker)	“O” (icebreaker)	“R” (icebreaker)
Length overall, m	12	25	31,5	16
Breadth overall, m	4,2	15	18,68	8,8
Depth, m	2,3	4,0	4,0	1,8
Draft according to design waterline, m	1,6	2,65	3,0	1,4
Displacement at waterline draft, m3	38,0	438	758,0 (incl. 29-ballast)	107,5 (incl. 29-ballast)
Maximum power consumed by the switchgear, kW	20	140	-	-
Maximum thickness of solid ice overcome by continuous sailing (pusher power), kW	25(220)	90(1000) with switchgear 43(1000) without switchgear	-	50(575)

“Tug+ icebreaking and ice-clearing attachments” combinations make it possible not only to effectively clear a channel laid by an icebreaker from broken ice, but also to independently lay channels in solid ice for guiding transport ships.
At the same time, the use of a rocking installation (RI) on the icebreaking and ice-clearing attachments makes it possible to increase icebreaking capability when moving in solid ice by approximately 2 times: when the icebreaking and ice-clearing attachment pr.1749 was operating in conjunction with a 1000 kW tug, the maximum thickness of solid ice when using the RI was 0,9 m, without use of RI – 0,43 m.
Taking into account construction costs and operating costs, icebreaking and ice-clearing attachments without RI were accepted for serial production.
The hull forms of the icebreaking and ice-clearing attachment pr.2158, intended primarily for cleaning and expanding the channels laid by the icebreaker, had a simplified flat-edged shape. The forms of the bow ensured that the ice floes were sunk, moved along the bottom and then tucked under the edges of the channel using an ice-breaking wedge.
At the bow end there were inclined knives for chopping off the uneven edges of the canal and expanding it up to 19 m.
Non-self-propelled icebreaking and ice-clearing attachments without RI can also be successfully used for laying channels in solid ice of relatively small thickness.