Wanting the best Precast Concrete Telecom Manhole Supplier?
The role of a telecom manhole is to remain undisturbed down under for decades, to exclude ground and water movement from the fiber and copper conduit within, and to allow the technician to have a clean access to the fiber and copper when a splice or repair is required.
If it works, no one is aware of it.
If it doesn’t, the problem is most likely not with the concrete, but with the concrete supplier who poured it.
This guide takes you step-by-step through the process of assessing your telecom manhole supplier to ensure your project does not fall into the second category, the one that isn’t.
Selecting a Supplier – More on the Process than the Spec Sheet
When purchasing, most buyers begin by comparing chamber size, load ratings and cost per unit.
That’s a good start, but it overlooks how the supplier is installing duct knockouts, how they describe the joints, and how they safeguard the inside of the chamber from groundwater that’s just beneath the surface in most parts of the UAE.
A telecom chamber isn’t just a concrete box with a lid.
A duct entry, each joint and every racking insert is a potential path for water to get to a splice closure, which it was never designed to touch.
An honest supplier reasons about the risk of cable damage, not the generic structural capacity, from the ground-up.
The one that does not does so a chamber that appears to be in good condition on the day it is delivered, and begins leaking, cracking at the knockouts or corroding at the racking inserts a few years into the service.
Be Sure and Get What You Need, Not More
It is good to know what type of chamber your network needs before you start comparing suppliers – not all precast manufacturers fill the entire spectrum.
Splice Chambers
Fiber or Copper splice closures are housed in Splice Chambers and require plenty of space inside the chamber, multiple walls for racking, and the environment inside the chamber must be dry and well-sealed as this is where the most water-sensitive part of the network is located, the splice tray.
Distribution and Handhole Chambers
Along the duct run, Distribution and Handhole Chambers are smaller access points intended for pulling cable through, but not splicing, and require an appropriate sized duct knockout based on the number of cables being pulled through.
Aggregation Chambers
Aggregation Chambers are located at a point where several duct banks meet, for example close to a central office, or a large street cabinet, and require the maximum feasible size, number of duct entries and racking to provide efficient, orderly cable management with dozens of cables without crossovers.
Handholes and Pull Boxes
Handholes and Pull Boxes are the smallest and most often used to supply single-duct runs to curbside cabinets and emphasize cover over interior space for a secure, tamper-proof enclosure.
After determining the type you require for your project, you can narrow your search for suppliers to those that specialize in manufacturing precast units for telecom applications, instead of just having it as a side product from a telecom general precast manufacturer.
Be Sure to Inquire About Duct Entry and Knockout Flexibility
Your duct layout drawings are not as generic as most duct layout drawings found in a catalog chamber.
Inquire about the method used by the supplier for duct entries; do they provide pre-cast knockout panels for the number and position of the duct count or do they assume that the installer will have to core through solid walls on site?
Coring after the delivery can lead to reduction of the amount of reinforcement and weakening the wall of the chamber in the most critical area.
The supplier that is able to manufacture knockouts according to your duct schedule is talking your language, whereas if they only make a handful of standard knockouts, they are asking you to design around them.
Discuss With Them How They Tackle the Challenge of Waterproofing and Sealing
It’s the one key point that’s most important and easiest to get wrong for a telecom chamber.
Inquire about the sealing of joint faces, the casting of waterstops into the joints and the sealing of duct entry points at the time the duct passes through a wall.
Inquire if they routinely use an external waterproofing membrane or if it’s requested.
If the supplier is giving you something to check later, he is using specific materials and methods, if not, he is giving you little to verify on site.
Examine Their Manufacturing Quality Control
The two chambers may be equal to paper, but they may have very different performances if they are cast differently.
Inquire about the placement and verification of racking inserts and duct knockouts prior to pour, and the curing process, as well as any inspections performed prior to a unit departing from the yard.
An installation crew will save a lot of time from making on-site drilling of concrete, which can lead to contact with reinforcement steel, by using a dense, well-cured interior finish that resists groundwater ingress and abrasion much better than a porous finish.
Request Engineered Drawings & Load Calculations
A good supplier will be able to produce drawings for each particular project, rather than a catalog cut sheet.
For telecom chambers, that translates to a guaranteed entry position, size of the duct, and a structural load rating that corresponds to the amount of traffic overhead or pedestrian or landscaped.
If the manufacturer is unable to provide drawings tailored to your duct schedule and site requirements, you probably aren’t getting a duct that was designed for your network.
Consult Operator Requirements for Familiarity in Comparison
Most telecom operators have their own approved chamber size, fit-out standards, access cover requirements – and if the chamber does not meet these requirements, it will be rejected at inspection despite being a good chamber.
Whether the supplier has ever produced chambers that have been approved for the network you are constructing for, and if they can supply compliance documentation to that network’s standards.
When an operator needs something but the supplier doesn’t, there is an added risk that becomes apparent at the very last minute, typically on commissioning.
Look Into Their References and Track Record
Mix design and reinforcement detailing indicate to you what a supplier can do.
In the completed installations, they tell you what they have delivered.
Request examples of chambers provided for other projects with a comparable number of ducts and site conditions and photos taken several months after installation, not on delivery day.
After a few years in the ground, a dry, sound, crack-free chamber tells more about a supplier’s quality than any spec sheet.
Signs and Symptoms That Should Not Be Ignored
The following are some warning signs that the supplier is not telecom-focused:
- Unclear response to the question of how the joints and seals are to be sealed.
- Unwillingness to share drawings specific to the duct in question.
- No quality control process in place to verify that knockout and racking placement will be correct prior to pour.
- Pricing that is significantly lower than the rest of the market with no explanation of the difference.
None of these is a crime in itself, but if two or three of them are present, this is a moment to reflect.
Integrating the Pieces Precast Concrete Telecom Manhole Supplier
The answer is to know which type of chamber your network requires, and to ensure that the supplier designs for entries into the duct, watertight joints, fit-out by the operator, and a track record of production of chambers that have performed in service, not just on a drawing, and are supported by actual quality control from the supplier’s manufacturing.
If done correctly, the chamber performs its intended function of sitting below ground, maintaining a dry environment and remaining out of sight and reach for decades.
