CLA-2 CO:R:CV:G: 084855 JLV; 841161

Linda H. Moorhouse
Dowty Corporation
177 Thorn Hill Road
Warrendale, Pennsylvania 15086

RE: Self-advancing hydraulic mine roof shield supports

Dear Ms. Moorhouse:

In a letter of May 15, 1989, you requested a ruling on the classification of certain self-advancing mine roof supports that are imported by Dowty Corporation, Warrendale, Pennsylvania, from the United Kingdom. Your request was forwarded to this office by the Regional Commissioner, New York, for our response on the classification issue under the Harmonized Tariff Schedule of the United States, Annotated (HTSUSA).


The merchandise involves three types of hydraulic supports described as "shield supports" that are "self- advancing, hydraulic supports" used in longwall mining operations. The literature describes these supports as self- advancing hydraulic 2-leg, 4-leg, and 4-leg chock-type mine roof supports. The supports consist of hydraulic cylinders placed between a steel floor beam and a roof beam containing a steel caving shield. The "legs" are the vertical supports for the overhead shield.

The supports are installed side by side in a long row in the mine in order to form a continuous overhead canopy which cantilevers over the excavating equipment (a conveyor and a

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coal shearing machine). The shearer, which usually slides along the top of the conveyor, shears off coal in a strip 20- 30 inches wide and pushes the chunks of coal onto the conveyor. This results in a 20-30 inch wide gap into which the conveyor is pushed by the mine roof supports. The hydraulic cylinders in the mine roof supports which support the overhead steel canopy are then retracted and the supports are sequentially advanced up to the armored conveyor as the shearer cuts away the coal. Thus, the conveyor and the mine roof supports are properly positioned for when the shearer cuts the coal on its return pass along the face.


What is the classification of a self-advancing, hydraulic mine roof support?


The key features of the mine roof support are its ability to provide support in case of movement of the mine roof, to reposition itself as materials are mined, and to advance the conveyor up to the area to be mined next. The principal function of the mine roof support is to provide protection and support in a mine. The repositioning of the conveyor is secondary to the support function.

Classification under various headings has been proposed: heading 8425, which provides, among other named machines, for jacks; heading 8428, which provides for other lifting and handling machinery; heading 8430, which provides, among other machinery, for certain leveling, excavating, and extracting machinery (other than self-propelled); and heading 8479, which provides for machines and mechanical appliances having individual functions, not specified or included elsewhere in chapter 84.

The principal function of the mine roof supports is that of protective support. They are not "jacks" because they do not lift or raise the mine roof. They are not excavating machinery because they do not attack or cut the earth's crust or the materials to be mined. They are not other lifting or handling machinery because their function is related to that of a static support system, such as a scaffolding.

The mine roof supports are mechanical devices. Absent a specific heading which describes the machinery, the appropriate tariff classification is in heading 8479 which

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provides for machines and mechanical appliances having individual functions, not specified or included elsewhere in chapter 84. Note 7, chapter 84, states that, subject to certain conditions not relevant in this case, a "machine the principal purpose of which is not described in any heading" is to be classified in heading 8479.


The self-advancing hydraulic mine roof supports are classified in subheading 8479.89.9090, HTSUSA, as other machines and mechanical appliances, other, other, and dutiable at 3.7 percent ad valorem.


John Durant, Director
Commercial Rulings Division

6cc: AD NY Seaport
2cc: Chief, CIE
1cc: NIS Alan Horowitz
1cc: AC, CO
1cc: Director, CommRulDiv
1cc: Reading File

LIBRARY: valentin
FILE NAME: 084855