From a radio communications perspective a confined space is anywhere where a reasonable line of sight cannot be maintained between radio devices and a transmitting mast.
This could refer to very cramped and restricted spaces, including those underground such as road tunnels, underground railways, utility tunnels and mines. However, it also covers spaces that may in themselves be relatively large and open, but are nevertheless cut off from major masts by complex layouts or obstacles such as thick concrete.
Every confined space engineering project needs to begin with an in depth understanding of the existing communications technologies that are currently in place and any that are planned for the future, along with a comprehensive understanding of the user requirements.
This information should be defined following a requirements gathering exercise carried out through user group workshops. It should include areas such as the identification of the parties involved in the project, its purpose/aim, all technical requirements, special features and an agreement on acceptance documentation and stakeholder sign-off.
Following this, a comprehensive survey of the environment in question should be carried out.
The survey determines factors including:
- Precise cable routes: cables must generally bend as little as possible, and larger diameter cables cannot always be threaded through a complex route.
- Mounting requirements: cables must be mounted away from other fixtures such as lighting and other metal structures
- Historical or other key features that must be avoided or preserved.
- Building structure and fabric: this affects both antenna signal and cabling routes.
- Handling and delivery: long runs of cable may be supplied on drums weighing over 1000kg and up to 3m in diameter so careful handling and delivery to the installation site is essential.
There are two main approaches when dealing with the challenges of confined spaces, and Simoco Wireless Solutions has a long heritage in developing bespoke confined space solutions to suit any space.
For spaces that are cut off, rather than cramped an additional antenna or antennas can be installed within the confined space, to create a kind of signal ‘hotspot’. This is therefore a common technique in settings such as the turbine hall at a power station.
Alternatively sophisticated radiating cables can be used in a ‘leaky feeder’ approach allowing the radio signal to radiate out in a pre-calculated manner for the frequency ranges in use by the system.
Confined space engineering in Action
These approaches are technology-agnostic; meaning they can be used across all standards of radio, from the latest Digital Mobile Radio (DMR) to standards such as Terrestrial Trunked Radio (TETRA) and GSM Cellular systems. In many cases, there are requirements for multiple different types of radio within a single organisation; maintenance and engineering teams may require one system, while members of the public may require FM or even MW radio for entertainment purposes, and provision for the new LTE-based Emergency Services Network may be required too.
As such, whatever the precise nature of confined spaces within your organisation, Simoco Wireless Solutions can engineer an integrated system that meets your needs, and delivers robust, resilient and reliable communication throughout.