Underground handhole vaults might be hidden out of sight, but they play a significant role in supporting essential infrastructure across industries. From keeping telecommunications networks running to enabling efficient power distribution, these small but important structures are indispensable.
If you’re new to the concept, this blog will explain what underground handhole vaults are, their purpose, the materials they’re made from, installation methods, and their benefits. We’ll also look at their applications across various industries, so you can see why they’re such a vital part of modern infrastructure.
What Are Underground Handhole Vaults?
At their core, underground handhole vaults are access points designed to house and protect cables, conduits, wires, or other infrastructure components beneath the ground. They essentially provide a compact space where maintenance teams can easily access buried utility lines without major excavation.
Unlike manholes, which are larger and allow for personnel entry, handholes are smaller. They usually operate as entry points for tools or equipment and don’t accommodate human occupation. These vaults are typically installed flush with the ground, covered with lids or covers, and are strategically placed in areas where regular access is necessary.
Purpose of Underground Handhole Vaults
The main function of an underground handhole vault is to protect critical utility systems while providing easy access for maintenance, inspection, or upgrades. Without these structures, servicing underground systems would require more invasive and time-consuming excavation, affecting both costs and surrounding infrastructure.
Here are some key purposes of handhole vaults:
- Housing Utility Lines – They secure cables and conduits underground, shielding them from weather, physical wear, or tampering.
- Facilitating Maintenance – The vaults allow utility workers to troubleshoot or upgrade systems without the need for complex digging.
- Organizing Infrastructure – They provide a neat, organized space for distributing and labeling lines, reducing downtime caused by confusion during repairs.
- Protecting Public Safety – By keeping wiring underground and secure, they reduce risks associated with exposed cables or wiring hazards.
Types of Underground Handhole Vaults
Underground handhole vaults can be customized for various applications depending on their intended use. Below are the most common types:
1. Standard Handhole Vaults
These are simple and compact structures designed for straightforward applications, such as housing telephone or network cables in residential areas.
2. Load-Bearing Vaults
These vaults are reinforced to handle heavy loads and are usually installed beneath roadways or parking lots. They protect utility systems from damage caused by vehicular traffic.
3. Traffic-Rated Vaults
Built with high-strength materials, these vaults are engineered specifically to withstand significant weight and are often used in areas with frequent vehicular movement.
4. Custom Vaults
Some applications require unique specifications, such as larger sizes or special designs, for housing complex utility systems or accommodating unusual terrain.
Materials Used in Underground Handhole Vaults
The choice of material for a handhole vault depends on factors like durability, load-bearing capacity, and environmental protection. Common materials include:
1. Concrete
Concrete is one of the most popular materials for handhole vaults due to its strength, affordability, and longevity. It’s commonly used in traffic-heavy areas where durability is essential.
2. Polymer Concrete
A combination of polymer resins and aggregates, this material provides enhanced resistance to chemicals and high compression strength. It’s ideal for industrial applications.
3. Plastic/HDPE (High-Density Polyethylene)
Lightweight yet durable, these vaults are corrosion-resistant and commonly used in regions with harsh environmental conditions. They are easy to install, which makes them a convenient choice for many sectors.
4. Fiberglass/Composite Materials
Fiberglass vaults are lightweight, corrosion-resistant, and highly versatile. They’re often used in applications where the vault won’t be subjected to heavy loads.
5. Steel/Metal Reinforcements
Though less common, steel-reinforced handhole vaults are sometimes used for additional support when placed in high-load areas.
Installation Process for Underground Handhole Vaults
Installing an underground handhole vault requires careful planning and adherence to safety regulations. Here’s an outline of a typical installation process:
Step 1: Site Assessment and Planning
Before installation begins, professionals assess the site to determine the vault’s suitable size, material, and location. This phase ensures that the vault aligns with local regulations and utility-routing plans.
Step 2: Excavation
A trench is excavated to the appropriate depth and dimensions to accommodate the vault, allowing room for leveling and backfilling.
Step 3: Bed Preparation
A layer of gravel or concrete is placed at the bottom of the excavation to ensure stability and drainage. This forms the foundation for the vault.
Step 4: Vault Placement
The vault is carefully lowered into the excavation site, often using specialized equipment, to ensure precision and stability.
Step 5: Connection and Backfilling
Cables and conduits are routed through the vault, and the appropriate connections are made. Backfill material is then applied around the vault to secure it in place.
Step 6: Final Inspection
After installation, the vault is inspected to confirm it meets safety and performance standards.
Benefits of Underground Handhole Vaults
Underground handhole vaults offer numerous advantages, from improving infrastructure efficiency to boosting public safety. Below are some key benefits:
1. Accessibility
By centralizing access to essential utility systems, these vaults make maintenance faster and less disruptive.
2. Durability
The tough materials used in handhole vaults protect cables and conduits from environmental damage, extending the life of utility systems.
3. Cost-Efficiency
Their ability to streamline repairs and reduce the need for invasive excavation significantly cuts maintenance costs.
4. Safety
Handhole vaults mitigate risks linked to exposed cables, ensuring both worker and public safety.
5. Aesthetics
By keeping wires and infrastructure underground, these vaults help maintain clean, clutter-free urban and rural environments.
Applications of Underground Handhole Vaults
Handhole vaults are ubiquitous in industries that rely heavily on underground utility networks. Here are some examples of their applications in key sectors:
Telecommunications
Telecommunications companies use these vaults to house fiber-optic cables, ensuring reliable high-speed internet and telephone service.
Utilities
Electrical utility providers rely on handhole vaults to store and protect power lines, transformers, and conduit networks.
Construction
Construction sites use temporary handhole vaults to route portable power or other utilities during project work.
Oil & Gas
Vaults in this industry serve to house pipelines and connection points, critical for distribution networks.
Transportation
They are commonly seen in roadway and transportation planning, offering safe and secure housings for traffic signal wiring, street lights, and other infrastructure.
Final Thoughts
Underground handhole vaults may go unnoticed, but their impact on improving infrastructure reliability and maintenance efficiency is significant. Whether in telecommunications, utilities, or construction, these unassuming structures ensure vital systems run smoothly and safely.
For companies and professionals involved in infrastructure projects, understanding the types, materials, installation methods, and use cases for handhole vaults is essential. With continual innovation in this field, these vaults are set to remain a critical component of our infrastructure for years to come.