Whether you are a well-established sewer contractor, a large city with an existing pipe inspection and rehabilitation department, or a small town / new business getting off the ground, it is important to weigh the pros and cons before making large capital investments. Buying the right equipment is the key to having good data, happy operators, and a smooth operation.
The goal of this guide is to answer any questions you may have about sewer system inspection equipment and help identify key features to look for based on your specific needs.
Here are some of the questions we answer:
- What is the difference between manhole cameras, drain cameras, push cameras, and crawlers?
- What types of projects do these crawlers help for?
- What do I need in a crawler?
- What do I need for software to make a good report?
- How much do these things cost?
- Where else besides a sewer are these crawlers being used?
- What are the different camera options?
There are many words that are used to describe pipe crawlers. Sewer cameras, Transporters, Mainline cameras, CCTV, or Tractor units. Within this guide, the term ‘Pipe Crawler’ will be exclusively used, however, all of these are used interchangeably.
Pipe crawlers are remotely controlled pipe inspection robots. Typically, crawlers will be mounted with pan/tilt cameras on them. There are cables attached to the crawler to deliver the camera feed, data, and in some cases, direct power to and from the crawler to the control station topside. Some controls may be from a truck-mounted computer, and some from a mobile workstation. Utilizing a distance tracking sensor in the tether reel, operators will receive live feedback of the crawlers’ position in the pipe. This is important for understanding where certain features are when the user locates and logs the anomaly for a targeted response.
Just as the pipes they are designed to enter, pipe crawlers come in a variety of sizes. The smallest options will fit into as small as a 4” pipe, but have far more limited capabilities than their larger counterparts . Typically smaller crawlers cannot drive as far, handle as much debris, or hold as large of payloads. To perform a proper pipe inspection, operators will need to find a crawler which is sized properly for the camera to be able to center inside the pipe. For smaller pipes, the camera centering is based on the wheels on the vehicle and camera mounting position. For larger crawlers, the camera can be raised and lowered to center itself via an arm. Some arms are robotic, allowing it to be controlled via topside controller, whereas others will rely on a manually placed arm before the pipe inspection begins.
Camera head centering allows for operators to view as much of the pipe as possible from a level facing camera or “home” position. This allows for a general understanding of the pipe’s condition without needing to pan or tilt the camera around. Once identifying a potential defect or anomaly that is worth exploring more from the home position, the user can adjust the camera, and in some cases use zoom functionality to look at defects more closely.
Camera head centering is also a requirement for certified inspections. Globally, there are several guiding associations on best practices for pipe inspections, such as NASSCO and WRc. These associations provide a standard methodology and shared language to help make comparison between pipes and inspection data easier. Part of this is to identify the location of defects easily, where the pan position, tilt position, and length count of the tether (how far into the pipe the crawler is).
To learn more about NASSCO PACP Certification
As pipe crawlers drive down a pipe, users are monitoring the video feed and other data on some sort of screen. Some crawlers operate with handheld controllers, some with laptop-style consoles, and some with full desk setups in the back of a truck or van. There are advantages and disadvantages to each type of pipe video inspection equipment, and the best one for you depends on your priorities. Some tablet controllers or consoles have video outputs and connection options, which allows the operator to easily interchange between a portable controller and mounted system.
- Most portable
- Easiest for new users to operate
- Limited reporting/data entry
- Most comfortable setup for operator
- Easy to customize to suit the operator
- Least flexible to get a truck to remote or difficult to access manholes
- Typically highest cost
- Somewhat portable
- Allow for data entry and full reporting
- Can be bulky and heavy
- Some have limited reporting features and are limited to one screen
Pipe Crawlers also have a variety of wheel options depending on their environment. Rubber wheels are most commonly used for the most common pipe materials (concrete, ductile iron, HDPE, corrugated steel). Track options are good for obstacles and areas with significant debris. Flaked carbide wheels are best for PVC and clay pipes. Pneumatic tires are best for mud, which are most commonly found in larger diameter stormwater pipes.
Pipe crawlers range in price based on the chosen add-ons. A typical budget for a portable pipe crawler is about $45,000 to $100,000 (USD), depending on the applications and features. Truck mounted crawlers can cost between $80,000 and 200,000, plus the cost of the truck itself, which can add an additional $50,000 to 150,000.
There are also other add-ons for pipe crawlers that are useful for pipe inspectors. The camera feed is the most commonly used sensor, however sometimes more detail is required. In these instances, integrated laser or LIDAR technology helps get extremely accurate results, but can be time consuming and expensive. Sonar technology helps in murky water environments, but is relatively inaccurate compared to laser. Photogrammetry (the stitching of camera footage together) is popular with aerial drone technology, and is being explored more with crawlers as a cost effective alternative to lasers with similar accuracy and lifelike representations of environments.
Laser Rings use software to take a series of images with a laser ring on the target to build the model. The sewer software company WinCan offers a module with this capability as an example. One setback of laser ring is that the full ring needs to be visible in the camera feed for it to register, limiting the diameter that it is effective in. The laser also needs to sit out in front of the pipe crawler’s camera, which typically leads to a design that has a ring sitting far out of the crawler, making it hard to fit into the pipe.
- Relatively low cost (~$10,000 with software to build the model)
- Easy for small diameter pipes
- Not useful in large diameter pipes
- Difficult to deploy in a pipe, particularly with smaller manholes/access
- Can be large files
- Does not work in water
Watch our Laser Ring Video
LIDAR uses laser pulses and calculates their time of flight to determine the distance that each beam has traveled. Taking the distances as points and converting them into a point cloud representation of the structures, users can now see the pipe as an accurate representation and easily measure details such as ovality of the pipe, sediment build-up, find defects, and compare changes over time to future scans. The downside of LIDAR is the current sensor cost and speed. Some LIDAR can take significantly longer to perform an inspection and generate large file sizes. However, the technology continues to improve and is a candidate to become a mainstay in the sewer industry.
- Extremely accurate
- Can offer wider range of pipe diameter capabilities
- High cost (Depends on model, $50,000 to $300,000)
- Slow speed
- Large Data files
- Does not work underwater
Sonar is an incredibly versatile tool that can be used in a broad range of applications, using sound waves to locate or map out objects and landscapes in the environment. Because sound travels further in water, imaging sonar sensors are best suited for underwater missions or submerged pipes. Sonar is ideal for determining the general condition of pipes, gathering data on ovality, sediment levels, and identifying major defects; but, do not provide the level of detail required to make condition assessment decisions on small defects. They are often referred to as the most important sensor on an ROV by ROV pilots.
- Works underwater
- Reliable and can work in large areas / large diameter pipes
- Can be costly ($10,000 to $200,000)
- Does not work in dry environments
- Not the most accurate
Photogrammetry is a process undertaken through the interpretation of photographs based on image overlap and parallax calculations. Using imagery to create 3D models of complex structures provides operators with detailed insights into the environments they are inspecting, and offer a great way to keep historical records or track and monitor degradation over time. Working underwater, a ROV is ideal for 3D archaelogical modelling, by capturing reliable images, and the ability to be deployed virtually anywhere without imposing risk to divers due to water hazards. Used in combination with sonar in low visibility conditions, the sonar footage can be overlayed with images, or in some cases, used alone to create a photogrammetric model.
- Most true-to-life representation
- Can be cost effective with manual processes, but that would be time consuming
- Can be expensive when automating model generation ($30,000-$500,000)
- Still very new technology (in pipes)
Push cameras are another tool for performing pipe inspections. Sometimes referred to as pushrod cameras, they look similar to a small crawler but do not have motors or driving capability. The wheels provide stability for the camera as the user pushes the rigid cable down the pipe. They offer a more cost effective and quick solution to pipe inspections. They also can fit into a smaller range of pipes, some as small as 1” diameter. Push cameras are also an excellent option where there are small bends, maneuvering around small diameter elbows.
The trade off is the lack of control over where the camera faces and the distance it can travel down the pipe. Most push cameras start to get into trouble at about 100 feet, especially if it is in a larger diameter pipe. If given a wide enough diameter, the push camera will coil within the pipe. Additionally, without the lift arm that is common on pipe crawlers, the camera can very easily get buried in debris or underwater, making it difficult to get a visual. Due to their ability to enter narrow diameter pipes (1-4”) a push camera is an excellent complement to a sewer crawler. Additionally, for a new contractor that primarily works in small diameter pipes, they might be the best option to start with as a budget-friendly solution. Push cameras cost between $15,000 and $45,000, depending on the features and capabilities.
A drain camera or borescope is the smallest format of camera for the water and wastewater industry. There are many options for this, with larger versions that can articulate, as well as smaller versions that simply get pushed down the drain of a sink. These are the lowest cost and simplest of options for getting eyes into a pipe. They will not be able to go very far and will easily be disrupted by obstacles or debris. These systems primarily act as a complimentary item in the toolbox, and are common for plumbers especially. Drain cameras are available on Amazon for as little as $40 but higher end units can cost as much as a few thousand dollars, depending on durability, range, and capability.
As the name dictates, zoom cameras are specifically designed with tremendous zoom capabilities. They typically are lowered by a tripod standing above a manhole, lining the camera up with the entrance to the pipe. The camera then uses a blend of optical and digital zoom to see hundreds of feet into the sewer. The results are dependent on the environment. Any bends in the pipe or physical defects can potentially block the camera from seeing beyond a certain point Albeit this is yet another quick and complimentary way to perform inspections and is a good tool to have available. Zoom cameras are typically a few thousand dollars to $20,000 depending on the capabilities.
There are several different reasons for looking in sewer and stormwater pipes. There are also several different companies that perform these types of inspections. The list below is not an exhaustive list, but gives a general overview of the common applications for pipe inspection equipment.
Proactive inspections are the best method for sewer and stormwater departments to manage their budgets effectively. Systematically inspecting the entire network of pipes allows the city to prioritize which pipes or which areas need the most attention, as well as which are in great condition and require no immediate work. If unable to monitor ongoing condition, unnoticed problems can create blockages, sinkholes, and major leaks have typically been problems long before the “big event.” Avoiding the big event means reducing major disruption of service, reducing critical personnel called out on overtime, and limiting costly repairs that could have been prevented with more cost effective rehabilitation methods such as lining, patching, or cleaning.
Infiltration and inflow (I&I) is a popular topic in the wastewater community. Identifying where water is flowing in and out of pipes, and where it is NOT supposed to be is a key goal to avoiding sewer overflows and leaks that lead to public harm. These inflows can come from a variety of sources, including tree roots penetrating pipes, poor utility planning leading to pipe boring going through existing wastewater pipes, or cracks and degradation over time from wear and tear. I&I is a problem that cannot be addressed by a full system replacement. Replacing entire networks of pipes is not possible, with the only way to approach the problem being an inspection of the system to prioritize targeted repairs based on most critical issues, and to proactively do so before they become emergencies.
The systematized inspection process is best supported by utilizing recommended approaches from the sewer associations like NASSCO. This common language and identification process allows for easy comparison across wide ranges of inspection data.
Talk to us about your pipe inspection projects.
Pipe cleaning is an excellent part of a wastewater management plan. Using jetters or vacuum trucks (link to information about these) to clean debris from pipes helps avoid blockages that lead to sewer overflows. Cleaning makes inspections more effective, as crawlers are able to navigate further into pipes and see the structural condition more easily. Cleaning also helps with rehabilitation of pipes, clearing the way for lining and patch methodologies.
To assess whether a pipe should be cleaned and whether it can be done safely, all of the cameras mentioned above can be used to assess this. Pipe crawlers are particularly useful for navigating above flows and over some obstructions and obstacles. After a cleaning is complete, a post-cleaning survey can help verify for the customer that the cleaning has indeed been completed.
Post-cleaning surveys are also an optimal time to perform inspections for I&I evaluations. Typically, truck mounted crawler crews are not sent at the same time as cleaning crews. Portable crawler systems that can integrate with a cleaning crew is a potential method to capture quality inspection data within the same crew, saving time and money on not sending a dedicated TV truck and crew to the same site.
When construction is about to begin on a certain site, engineering firms will often perform surveys over existing infrastructure in that area to determine best strategies for moving forward with the project. A piece of that puzzle is the underground infrastructure. Pipe crawler cameras can help evaluate the condition and the safety of moving ahead with the project.
One example of a reason for a pre-construction inspection is when looking for utility lines, fiber optic lines, or gas lines that run underground. If these are not known, then there is potential for loss of service, or worse, if an excavator strikes the line. Utility locators are also helpful tools, but won’t be an effective option for looking inside of the pipe.
After a pipe rehabilitation project or a new build project, it is important to verify the condition of the work. Newly installed pipes have a risk of sagging into the freshly dug ground. An inclinometer on a pipe crawler is an excellent way to verify that this is not occurring, by monitoring if the pipe is on more than a 1-2 degree angle during the inspection. The crawler can also inspect the joints to ensure they are intact.
Post lining surveys can verify there are no holes or bubbles in the lining, verify cuts from a cutter opening laterals, and even some cases where pipe crawlers are used to pull liners through pipes. Crews that are performing the rehabilitation can benefit from having a portable crawler on hand to perform these verifications.
Even with the most proactive inspection programs and rehabilitation programs, there will still be emergencies to respond to. Whether it is a water main break, a noticeable leak that is causing environmental harm, sinkholes, or blockages causing sewer overflows, these issues need eyes on the situation fast.
Pipe crawler cameras can help to identify the problem, which allows crews to quickly decide on which equipment and strategy is best suited to solve the issue. There is no one size fits all solution to each emergency inspection, so the more tools on hand, the better. Some crawlers are fully submersible and depth rated, which is important in scenarios where there is no option but to try and get eyes through water. For compliant inspection reporting, like NASSCO’s PACP system, you should not perform inspections when the pipe is more than 25% full of water. However, in the case of an emergency, certified inspection reporting is not the goal. , The goal is to solve the problem at hand, and that is where having a fully submersible tool can be a helpful option.
While pipe crawlers were tailor made for sewers and stormwater pipes, they have also found useful cases for their applications within other structures. Confined space entry is a dangerous task for humans. Depending on the structure, humans may be put into danger by being exposed to dangerous gasses and small areas with limited exit points. On top of the safety risk, confined space professionals are expensive to hire and it can be inconvenient to get them to a specific structure.
Pipe crawlers provide a safe, easy to operate, and cost effective method for inspecting these structures. Examples include wind turbine blades, tunnels, and ducts. Tunnels dug by insurgents have been explored with pipe crawlers in various parts of the world by defense forces. Ducts in nuclear power plants can be dozens of feet long and only a foot or two in diameter. They are typically hot and high in radioactivity, which are better suited for robotics to enter rather than humans.
For pipes in difficult to reach environments, such as on dam intake structures, certain pipe crawlers can perform well in. In these instances, mobile crawlers which operate on batteries rather than direct power are especially effective. An example was a project that Pipe Trekker participated in, where the crawler was deployed into 24”-36” diameter pipes, about 300’ long, by a diver 90’ underwater. The goal was to evaluate the pipe condition and inspect the gate at the end. This application was only possible with a depth rated crawler.
Now that you have learned about the different technologies for gathering inspection data and the reasons you want to gather the data, the big question is how to put it all together? The goal of the survey plays a big role in what software or data recording solution is best. There are many different brands of software available, ranging in their capabilities. Here is a link to more information about a few of those options (link to Pipe Trekker article about software options)
The main software capabilities to look at are:
- Do I want to add notes about each defect along with the photos and videos as I inspect
- Do I want the inspection to be NASSCO certified
- Do I want to inspect other structures such as manholes and laterals
- Do I want to build a map / georeference my findings
- Do I want to generate 3D models
- Do I want to share this information via the cloud with my client or from the field to in-office inspectors
- Do I want to use artificial intelligence (AI) to evaluate the inspection footage automatically for common defects to help reduce human error and speed up the inspection process
Adding annotations and comments along the inspection is a feature in every inspection software that operates from tablets, larger consoles, or truck mounted solutions. In some cases, more portable handheld controllers, like the smallest control option from Pipe Trekker, simply provide a streamlined camera feed. . The advantage of this solution is that it is extremely easy for the operator and the most straightforward process. For simple surveys or surveys without a thorough inspection goal, such as a post construction survey, turbine blade inspection or emergency response application, this is the ideal setup.
For thorough evaluations of I&I and maintenance planning, or for systematic inspections as part of cleaning surveys, it is better to have the additional reporting functionality. Software brands that provide this capability include Pipe Trekker, WinCan, CTSpec, SewerAI, ITPipes, POSM, GraniteNet, and more. There are advantages and disadvantages to each. WinCan is the global leader and has the widest range of offerings, so this guide will focus on them and their modules.
WinCan offers many different languages for their software, and compliance with their reporting for programs like NASSCO / PACP. WinCan’s Advanced and Expert licenses include integrations for manhole and lateral (LACP/MACP) evaluations. WinCan’s Expert package also has GIS integrations, with programs like ArcGIS, allowing for mapping capabilities. WinCan has laser modules to help with 3D modeling and AI modules for streamlined inspection processes. WinCan also has cloud computing options for teams that want to have their primary inspection operator at the office.
We recommend getting demos of the various software options available to understand what is best for your organization. We integrate with the majority of options and are happy to help provide recommendations based on your business needs.
Need a Crawler for your next pipe inspection?
- Maintenance Planning (Infiltration & Inflow Evaluation)
- Pre and Post Cleaning Survey
- Pre-construction evaluation
- Post-Construction / Lining / Rehabilitation Survey
- Emergency Response (Blockages, Sinkholes, Major Leaks)
- Confined Spaces (Wind Turbines, Tunnels, Ducts)
Pipe Trekker offers a range of capabilities across the various applications. There are a few questions that you can ask yourself in addition to the earlier information to help find the best setup for your needs.
- Smaller than 6” - Consider Push Cameras and Drain Cameras
- 6” and above - A-150 Pipe Crawler (Link each of these to their product pages)
- 8” and above - A-200 Pipe Crawler
- Mostly 6”-24” - A-150 Pipe Crawler
- Mostly larger diameter - A-200 Pipe Crawler
- A mix of all - Buy both!
- Less than 100’ - Push camera might work well
- 100’-650’ - A-150 / A-200
- Up to 1,000’ - A-200
- 1,000’+ - Contact us for specialized recommendations
Concrete, Ductile Iron, HDPE, Brick, Wood - Rubber Corrugated Steel, Large Diameter - Tracks, Pneumatic Wheels, Spacer Kit PVC, Clay - Carbide Wheels
What is more important - to be as mobile as possible or to have the convenience of a powered reel?
The S packages for the A-150 and A-200 are the champion products for portability and mobility. The tether reel is approximately 50 lbs depending on the length, and the handheld controller is extremely easy to get around and light enough to handle for extended use. The whole setup is battery operated, with 4 or more hours of run time on a single charge. Retrieval is easy with active freewheel mode on the crawlers allowing you to weightlessly wind the tether back up.
For more traditional inspection setups, using Pipe Trekker’s powered reel makes retrieval even easier, since the reel is capable of automatically bringing the tether back. This setup also helps deploy the tether out, providing a boost for the crawler to get through tough environments like mud or silt. The reel also allows for hybrid power delivery, meaning either of Pipe Treker’s A-Series can be charged via the tether for infinite run time.
The X package for the A-150 and A-200 include a specialized rugged tablet controller with a license to Pipe Trekker Control software. This Control software allows for reporting capabilities and annotations during the inspection for more organized data. The tablet also integrates nicely into truck setups and with the majority of third party software.
Another add-on to consider is the rear camera for the A-200, which allows operators to see behind you during retrieval. The rear camera on the A-200 is helpful for navigating around 90 degree bends in pipes or to ensure the tether does not get coiled in the crawler or jam up the pipe if it is not being retracted.
Concerned about training? Our crawler specialists can walk you through how to operate the systems and we have a library of training videos to support you. The intuitive controls take just minutes to master but you want the peace of mind to know that there’s a team here to help if you need it.
See our customer reviews