tractor as soon as it is feasible after their unsatisfactory condition is evident. Replacements shall not be made in any season definitely unfavorable for planting the kinds of plants involved. At the conclusion of the establishment period the engineer will make an inspection of the work to determine the condition of plants. All plants then not in a healthy, growing condition will be noted and the contractor so advised. As soon as seasonal conditions permit, all plants so noted and which are still not in a healthy, growing condition, shall be removed from the site and replaced with plants of the same kinds and sizes as originally specified. Such replacements shall be made in the same manner as specified for the original planting; the cost to be borne by the contractor.

950-3.6 CLEAN-UP. Any soil, manure, peat, or similar material which has been brought onto paved areas by hauling operations or otherwise shall be removed promptly, keeping these areas clean at all times. Upon completion of the planting, all excess soil, stones, and debris which has not previously been cleaned up shall be removed from the site or disposed of, as directed by the engineer. All ground areas disturbed as a result of planting operations shall be restored to their original condition or to the desired new appearance, as directed by the engineer.

METHOD OF MEASUREMENT

950-4.1 Trees, shrubs, and vines shall be measured in units of each plant delivered and planted. The list showing the quantities and unit costs of plants shall be listed and numbered in accordance with the List of Required Plants, as contained in the special provisions. Materials such as topsoil, peat, manure, inorganic fertilizer, lime, water, and drain tile and materials for guying, staking, mulching, and wrapping shall be considered as incidental to the planting operations. Measurement for transplanting existing trees and shrubs shall be in units of each plant satisfactorily transplanted.

BASIS OF PAYMENT

950-5.1 Payment for trees, shrubs, hedge plants, and vines will be made on the basis of unit contract prices for plants accepted at the time of final inspection. Such payment shall include costs of inspecting; furnishing and planting trees, shrubs, and vines; furnishing and incorporating topsoil, peat, manure, inorganic fertilizer, lime, water, and drain tile as specified herein; furnishing materials and labor for guying, staking, mulching, pruning, and wrapping; and establishment of plants until the time of final inspection. It shall include all labor, equipment, tools, and incidentals necessary to complete the planting operations. Payment for transplanting existing trees and shrubs will be made at the contract price for each plant satisfactorily transplanted. Such payment shall include furnishing all materials, labor, and equipment necessary for this operation.

Payment will be made under:

Item T-950-5.1 Trees, Shrubs, Hedge Plants, or Vines-per unit.

ITEM T-951 TREE WELLS AND ROOT PROTECTION

DESCRIPTION

951-1.1 This item shall consist of furnishing all material, equipment, and labor required for the spreading of the porous aggregate layer, and for the construction of tree wells for the protection of selected trees or shrubs as specified herein at locations shown on the plans.

MATERIALS

951-2.1 STONE. If required, the material for tree wells shall consist of clean, hard, stones of a kind known to be durable, and shall be subject to the approval of the engineer. Stones, except those used in pinning and filling interstices in the heart of walls, shall have minimum thicknesses of six (6) inches, minimum widths of twelve (12) inches, and minimum lengths of fifteen (15) inches. In the lower courses, stones shall have minimum volumes of one (1) cubic foot. 951-2.2 POROUS MATERIAL FOR TREE-ROOT PROTECTION. If required, the material for root protection shall be broken stone or washed gravel ranging from 2 to 2 inches in size. Material to be placed above this course to choke the porous layer shall be sand, straw, or some other suitable material approved by the engineer.

951-2.3 TILE. Tile, if required, shall be first quality, hardburned, agricultural tile, four (4) inches inside diameter.

CONSTRUCTION METHODS

951-3.1. GENERAL. The area for tree-root protection shall be considered as that over which the branches spread. It shall be cleaned thoroughly of all vegetation. Porous material, when required, shall be spread loosely over the area to the depth specified below. Sufficient care shall be taken that the trees are not scarred or otherwise damaged by construction operations.

951-3.2 TREES ABOVE GRADE LEVEL. Where the existing grade at the base of the tree trunk is above the required finished grade level, the ground from the outer edge of the area of tree-root protection shall be sloped to the surrounding grade level without abrupt change in grade.

951–3.3. TREES BELOW GRADE LEVEL. (a) Where existing grades beneath the spread of the branches are less than eight (8) inches below the finished grade level, the area shall be brought

to grade level with soil similar to that used for surrounding finished grading.

(b) Where existing grades beneath the spread of branches are eight (8) inches or more below the finished grade level, a layer of porous material for tree-root protection as specified above shall be spread over the area to the following depths:

This layer of porous aggregate shall then be covered with a layer of sand or straw to a depth of about one (1) inch to form a compact mat over it. At the outer ring or edge and above the porous aggregate layer, four (4) inch agricultural tile, as specified above, shall be placed in upright positions, approximately eight (8) feet apart, extending from the aggregate layer to the finished grade level. Tile shall be filled with coarse sand to permit the passage of air to the root system. Materials for filling to the finished grade level shall be in accordance with those specified for adjacent areas.

951-3.4 TREE WELLS. Tree wells of dry rubble masonry shall be constructed in accordance with the location dimensions and arrangements shown on the plan, or as directed by the engineer.

METHOD OF MEASUREMENT

951-4.1 The yardage of porous material for tree-root protection to be paid for shall be the number of cubic yards of approved porous material placed in tree-root protections, measured in the vehicle at point of delivery, and accepted.

951-4.2 The yardage dry rubble masonry to be paid for shall be the number of cubic yards complete in place and accepted. Projections extending beyond the faces of walls shall not be included. In computing the yardage for payment, the dimensions used shall be those shown on the plans or ordered in writing by the engineer. No deductions will be made for weep holes, drain pipe, or other openings of less than two (2) square feet in area.

BASIS OF PAYMENT

951-5.1 The yardage of porous material for tree-root protection, measured as provided above, shall be paid for at the contract unit price per cubic yard for “Porous Material for Tree-Root Protection," which price and payment shall constitute full compensation for cleaning the ground surface; for placing the porous fill; for procuring and deliver

ing all materials; and for all labor, equipment, tools, and incidentals necessary to complete the item, except masonry in tree wells and soil fill. 951-5.2 The yardage of masonry in tree wells, determined as provided above, shall be paid for at the contract unit price per cubic yard for "Dry Rubble Masonry," which price and payment shall be full compensation for furnishing and placing all material; and for all labor, equipment, tools, and incidentals necessary to complete the item.

951-5.3 Subsoil, topsoil, and other materials not included above but which are used in bringing the area to finished grade shall be considered as part of the grading operations for adjacent areas, and payment therefor shall be included in that item.

Payment will be made under:

Item T-951-5.1

Porous Material for Tree Root Protection-per cubic yard.

Item T-951-5.2 Dry Rubble Masonry-per cubic yard.

DIVISION V-LIGHTING INSTALLATION

ITEM L-101 INSTALLATION OF AIRPORT 36-INCH ROTATING BEACON

DESCRIPTION

101-1.1 This item shall consist of an airport 36-inch rotating beacon, furnished and installed in accordance with this specification at the location, and in conformity with the design and dimensions shown on the plans. This work shall include the mounting, leveling, servicing, wiring, painting, and testing of the beacon and all incidentals necessary to place it in operating condition as a completed unit to the satisfaction of the engineer. This item shall include a mounting platform, if stipulated on the plans.

101-2.1

MATERIALS

BEACON. The airport rotating beacon shall conform to Specification CAA-291, "Specification for Beacons, 36-inch Doubleend Type," with clear and green lenses, except less code flashing mechanism unless specified otherwise. Where specified, the code flashing mechanism shall consist of a contactor and cam cut to flash the code signal assigned to the airport.

When contractor's bid is based on an approved unit, factory inspection, sample unit and serial number requirements are waived.

When contractor's bid is based on a 36-inch rotating beacon not previously approved, the factory inspection and tests and sample unit requirements described in Specification CAA-291 shall not be waived.

101-2.2 PANEL BOARDS AND BREAKERS. Panel boards and breakers shall conform to the requirements of Federal Specification W-P-131, Class 1.

101-2.3 WEATHERPROOF CABINETS. The weatherproof cabinets shall conform to National Electric Manufacturers Standards, and shall be constructed of steel not thinner than No. 16 U. S. S. gauge. 101-2.4 WIRE. Wire in conduit above ground shall conform to the requirements of Federal Specification J-C-103, Type R or RH, and shall be of the size, number of conductors, and service voltage shown on the plans or proposal.

101-2.5 CONDUIT. Rigid steel conduit and fittings shall conform to the requirements of Federal Specification WW-C-581.