What are Fiber handholes
Fiber Handhole is a shallow version of manhole that used in fiber optic infrastructure and telecommunication projects and shall be provided to facilitate optical fiber cable blowing, jointing and storing loops of fiber cable for future use during maintenance activities.
Fiber Handholes shall be rectangular of square as per intra-city specifications. Handhole body and cover ring shall be suitable for corresponding loading. Handholes shall be of adequate size to accommodate number of joint closures and associated loops for each OFC specified in approved for construction drawings.
In general and specifically for inter-city routes, the handholes shall be installed such that the lid would be at the level of ground surface. Handholes shall be installed over well compacted ground and over a layer of concrete base. The entry of the duct into handholes shall be smooth and at its floor level. Sharp bends to force the entry shall be avoided. Ducts shall enter the handholes in a single layer and in the sequence.
All openings after installation of ducts shall be closed with cement grout or equivalent method to prevent entry of rodents, snakes, insects etc.
Size of hand-holes depends upon the telecom operators. Telecom companies use handhole according to their site location and areas. Handholes are available of different sizes. The standard handholes sizes have inner dimensions- Length(in)- 24 width(in)-36 depth(in)-26,
Length(in)- 17 width(in)-30 depth(in)-24,
Length(in)- 30 width(in)-48 depth(in)-36,
Handholes also available in size- As per company construction guide line.
Handholes Covers: The covers are made from composite with hex bolt fixing for the purpose of they may removed or replaced ,
Handholes Metal Accessories: Hand-holes metal accessories shall include , cabinet base blanking plate, bolts, nuts, lock washers, spacing washers pulling-in eyelets, sump hole grill cover.
Fiber handhole Type 1 basic components:
• Side Panels and Hex Fasteners
• Composite Cover with Hex Fastener Bolt-Down
Fiber Handhole Type 2 basic components:
• Side Panels and Plastic climp Fastener
• Handhole Cover with Hex Fastener Bolt-Down
Excavation Limits and Requirements:
The width and length of the excavation hole shall be sufficient to permit the entire bottom surface of the handhole sleeve to be set level, and then the backfill to be placed and compacted as specified. When rock or unsuitable foundation material is encountered at the established grade,and shall be reasonably free of foreign materials, rubbish, debris, etc. Frozen clumps, oversized stone, rock, concrete, bituminous chunks, or other unsuitable materials may prevent a thorough compaction or increase the risk of after settlement. additional materials are to be removed as specified or as directed by the soil engineer to ensure an acceptable foundation.
Standards For Underground 1¼” or 2″ Conduit Installation to a Handhole
Conduit lation for optical fiber cable
All conduits will be home run back to existing underground, or into a building to a Cable Tray or Telecommunications Room.
The minimum 90-degree bend radius for conduit is 6 times the internal diameter of the conduit.
Conduits entering a Vault must enter the body of the vault. Conduits must never enter the Traffic Ring.
Conduits must maintain a 12″ separation from other conduits (Electrical, Gas, Etc.).
For a conduit that is placed 12″ deep, detectable tape is to be placed at 8″ deep.
Install pull cords in all conduit. When pulling cable in conduit install a pull cord with the cable so additional cable can be installed later if needed.
When adding cable, add to occupied conduits with available space before using an empty conduit
All handholes serving as an endpoint shall have a 3/8″ ground rod.
Ground rod should be 4’ long, and are to be driven into the ground leaving 4″ above ground.
Ground rods must connect to the existing grounding infrastructure in the vault system with a #6
copper ground conductor.
Handhole Specific Details
Handholes may be used only when the maximum number of conduits on that route is never expected to exceed a single 2” conduit.
Handhole cover shall be labeled “TELECOM”or “COMMUNICATIONS”.
Install Handholes as required in conduit runs so that the distance between pull points is less than 200 feet.
Install Handholes in conduit runs so that a run of conduit does not contain more than the equivalent of two (2) ninety degree bends (180 degrees total) between pull points.
Install Handholes only in straight sections of conduit, not in lieu of a bend.
Each conduit entering and exiting a handhole shall be in direct alignment.
Conduits terminating in a handhole shall end 4″ below the base of the cover.
Electrical service is not to be added to a telcom handhole.
Handhole Bedding: All bedding materials shall be carefully compacted into place. Bedding requirements shall include mechanical compaction of sand and gravel material when specified. A 6 inch granular base of compacted crushed rock or granular materials; at which 100% passes a 3/8 inch sieve; and a maximum of 5% passes a number 10 sieve, shall be placed on compacted subgrade under the proposed handhole unit. The subgrade shall be compacted as directed by the soil engineer. When the bottom of the excavation is soft, The excavation can then be brought back up to the prescribed loading grade with a thoroughly compacted granular material.
Placing of the handhole: Placing and installing of the fiberknct type 1 and type 2 handhole: Side panels are set by hand. or go through with mechanical lifting aid when comes to a heavy handhole unit.
Handhole Backfilling Operations: All handhole excavations shall be backfilled to restore pre-existing conditions, or to the final grade as specified by the owner. Backfill material shall be a granular type as required by the soils engineer, Backfill shall be placed to the desired grade height, but shall not cover the top surface of the handhole unit.
In Compaction of the materials within the encasement zones of the handhole unit shall be achieved by hand or through the use of light duty electric or pneumatic tools only. The use of roller type compaction equipment and heavy construction equipment to compact backfill may cause damage to the handhole sleeve.
FiberKnct Handholes are composite reinforced chambers, utilized as connecting points, from primary cables to secondary cable distribution joints and cabinet terminating points etc. Handholes shall be constructed in a recognized and approved manner from top quality materials in accordance with the appropriate international standards. Design of manholes and hand-holes shall be as per approved for construction drawings issued by construction company or network provider.