Robots used to inspect drainage systems

This year, the city will repair water drainage systems at 250 locations. In this mos.ru interview, Konstantin Ishkhanyan, Director General of water drainage systems operator Mosvodostok, discusses the reconstruction of water drainage systems under the My Street programme, Mars-type exploration vehicles for inspecting these systems and the work of utility services during the summer rain season.

Question: Mr Ishkhanyan, how many water drainage systems will the city reconstruct this year?

Konstantin Ishkhanyan: Mosvodostok is to conduct scheduled repairs at 250 locations under its general annual plan. This includes 119 areas that have been repeatedly inundated in the past few years. The list of projects includes rebuilding some water drainage systems, expanding them, and building new sections where necessary.

The combined length of the system is over 7,700 kilometres long.

Water drainage systems include water-intake grates that you can see on the roads. They are a ramified and vast water-offtake system. Some water drainage pipes have a diameter of four metres, and some pipes have a 20-centimetre cross-section. Each section of the system has its own purification, troubleshooting and repair methods. For example, our employees inspect river collectors where small rivers flow; they clean and repair these collectors in winter. The water levels drop in cold weather, and people can work in the pipes.

We don’t use any equipment for flushing and repairing pipes in the winter because this equipment can only operate when temperatures are at least minus seven degrees Celsius. So we flush and reconstruct pipes using equipment when it warms up. We suspend the process after subzero temperatures set in.   

Question: How do you know when to repair or upgrade a specific pipe section? How do you gauge the state of water drainage systems?

Konstantin Ishkhanyan: As I mentioned, our experts inspect large pipes with a diameter of up to four metres. And we use robots to inspect water drainage pipes with a small diameter.

Small wheeled devices with lights and video cameras that can rotate 360 degrees move through narrow pipes. They act like the Mars exploration vehicles of the city’s water drainage systems and provide video footage from areas that cannot be accessed by people.

Since early 2017, we used robots to inspect most water drainage systems in areas covered by the My Street programme. They act as Mars exploration vehicles of the city’s water drainage systems.

We used such a robot for the first time in 2004 with positive results. But one robot is not enough to inspect 7,700 kilometres. We have deployed more remote controlled robotic inspectors. Since early 2017, we have been running five systems. Each comes complete with a mobile laboratory/observation post. This mobile laboratory is actually a vehicle with a monitor and a workstation for operators who control the robot underground and watch the video footage. Experts record any damaged pipe sections using the robot’s data. The vehicle can also recharge the robot or plug it into an electric outlet. The latter uses a 70-100-metre cable trailing behind the robot. These robots usually inspect short sections of water drainage systems.

Question: Do you also use robots to inspect water drainage systems on streets that are now being improved?

Konstantin Ishkhanyan: Preliminary pipe assessments are our top priority. We used robots to inspect most drainage systems in areas covered by the My Street programme.

Question: Do water drainage systems function well on the streets that were improved last year? Can they be repaired in an emergency without digging up the street?

Konstantin Ishkhanyan: The new drainage systems are working smoothly on streets that have already been improved. In an emergency, we can do repairs without digging up problem sections. We will not likely have to dig up any improved streets.

Question: You noted 119 formerly flooded sections, due to be repaired this year. Can you say a few more words about them, and how did you identify these sections?

Konstantin Ishkhanyan: After analysing flooding trends in the past few years, we listed 119 priority locations, mostly part of streets and roads, and some in courtyards.

Most of these areas have no drains or drains that can’t handle all incoming water; and so a flood.

Here are just a few problem areas. A small section of Khokhlovsky Pereulok is flooded due to a depression, and the systems have low capacity. An area of 1905 Goda Street has no such system and so is always flooded. Water also builds up on sections of Moskvoretskaya Embankment, Yuzhnoportovaya Street and at the intersection of Kaspiiskaya and Kantemirovskaya streets for the same reason. Most problem sections are reported in the Central, Eastern and Southeastern Administrative Areas. Southern and western districts and Zelenograd have identified fewer flood points than the others.

Mosvodostok lists 198 depressions where water accumulates during low-intensity and high-intensity rains. We’ve added 46 to the above 119 high-priority locations. But these problem areas will be reduced appreciably after construction projects are complete.

Our teams monitor flood-prone areas all the time, and city residents can also report them on the hotline service. We focus on flooded areas around the city’s transport system, including public transit-route areas and near bus and tram stops.

In August last year the city was hit by heavy rains that broke 140 year old records. In several hours, the streets were drenched with 120 percent of normal monthly precipitation. Much more water accumulated more often. We learned from that experience, and we have prepared for the upcoming rain season.

Question: And how has the city prepared for the upcoming downpours?

Konstantin Ishkhanyan: First of all, we have completed our seasonal maintenance, we have cleaned and repaired pipelines and prepared them for the flood and summer season. Waste that could have clogged the system together with melted snow was removed from open waterfronts. Second, we drafted a protocol for flood prevention with municipal and district-level utility agencies, including the Zhilishchnik housing maintenance agency, the Gormost bridge-and-park maintenance company, the Motor Roads agency and sewer operator Mosvodokanal, as well as the administrations of administrative areas and city districts.

Over 350 emergency response teams (over 1,000 experts) from our company will work 24 hours a day. They use 250 pieces of equipment, including water pumps and other specialised equipment. This will include 2,800 employees of municipal and district-level utility agencies.

The teams will respond quickly, and they will be posted to flood-prone areas based on the forecast. By the way, I’d like to remind city residents that they can call 8 (495) 657 8703 24/7 to report street floods. I’m confident that our work will help the city overcome any big issues, even the most unpleasant ones.

Question: Mr Ishkhanyan, the city resumed the My Street programme in April. How are you improving water drainage systems?

Konstantin Ishkhanyan: We upgrade these systems prior to the improvement projects to avoid hampering the work. These projects top the list. Since early 2017, we have been rebuilding the drainage systems at 22 locations in the My Street programme, mostly streets in the central districts. (Editor’s Note: Apart from rebuilding the drainage systems, the new sections will be built in all areas covered by the My Street programme. The Department for Major Housing Repairs is implementing this project).

Our teams have worked on the Valovaya, Korovy Val, Zemlyanoi Val, Sadovo-Chernogryazskaya Streets, Chistoprudny, Petrovsky and Sretensky Boulevards, all parts of the Garden and Boulevard Rings.

Question: What technology do you use?

Konstantin Ishkhanyan: We use the open and closed methods for upgrading the systems. Under the first method, we conduct excavation. This is more expensive and takes more time. But it is impossible to avoid excavation when old systems are seriously damaged or have basically disintegrated and need to be replaced completely. First, we dig trenches, remove damaged pipe sections and install new and more durable pipes.

Sometimes it’s impossible to upgrade worn-out systems by digging trenches, especially in central districts notorious for high-density construction projects and where there are many historical landmarks. This is because many other utility mains are also located underground, and these mains could be damaged if we dig deep trenches. So we prefer not to dig trenches in central Moscow.

The capacity of water drainage systems increases by 20-30 percent after the pipes are repaired or replaced without any trench-digging

Question: What are the basics of the trench-free method and what are its advantages?

Konstantin Ishkhanyan: We use the following two closed reconstruction methods. Under the first, we keep the old pipes and insert new polymer fiberglass-reinforced plastic hoses. This is called a polymer-hose upgrade. During polymerisation, the fiberglass-reinforced plastic hose sticks to the walls of the old water pipes and forms a new internal plastic pipe.

Under the second method, we remove the old pipe and replace it with a new plastic water pipe. We dig a starting pit and a receiving pit. Special trench-free pipe-laying equipment is placed inside the pit, and a new pipe is laid along the old pipeline route.

We are unable to increase the diameter of water pipes while upgrading them. If necessary, we can lay pipes with a larger diameter using the trench-free method.

The closed method is reliable, simple and helps save money. We don’t dig any large trenches and do not damage other utility mains. This work does not close streets and doesn’t obstruct traffic. We don’t damage other renovated street sections or any new landscaping.

Many drainage systems were laid in the 1950s and 60s in Moscow. Although they are in reasonable condition, the inner surface of these pipes is covered with cracks and bulges hampering the rapid flow of water

Question: What results does this work produce?

Konstantin Ishkhanyan: First of all, the capacity of water drainage systems increases by 20-30 percent after pipes are upgraded or replaced without any trench-digging, and water flows much faster. Of the 22 water drainage system sections included in the My Street programme, we upgraded 17 and repaired only five, replacing the pipes completely.

Many drainage systems were laid in the 1950s and the 60s in Moscow. Although they are in reasonable condition, the inner surface of these pipes is covered with cracks and bulges hampering the rapid flow of water. After upgrades, all these cracks are eliminated, and the bulges are smoothed over. The trench-free pipeline-laying method makes it possible to install pipes with a larger diameter, to replace damaged and dated sections with new more durable pipes with increased capacity.

I’d like to note that we have maintained the city drainage system pretty well; most of it only needs to be strengthened and maintained rather than replaced completely. Some of old Moscow’s water drainage systems were laid in the early 20^th century. They remain operational due to proper maintenance, operation and timely upgrades. For example, one of the oldest systems, laid in 1902, is in Alexander Nevsky Pereulok.

This year, several hundred additional water-intake grates will be installed under the My Street programme, with due consideration for large-scale works.

Question: Will you install new water-intake grates in areas being improved under the My Street programme?

Konstantin Ishkhanyan: It’s inaccurate to assume that additional water-intake grates always remove rainwater more quickly and improve the performance of the system. This is not necessarily so. Water-intake grates are installed with due consideration for various standards, terrain specifics, water collection areas and street gradient angles.

We install grates at optimal locations where rainwater or melted snow accumulate. In some cases, we have to relocate these grates or install additional ones. But we don’t have to do this in all areas covered by the street improvement projects. This year, several hundred additional water-intake grates will be installed under the My Street programme, with due consideration for large-scale works.

Question: In some cases, substandard construction disrupts the operation of the systems. How will you monitor this process?

Konstantin Ishkhanyan: We stipulate our own technical requirements while drafting street improvement design plans and projects. After studying the projects, we see to it that our remarks are taken into consideration. We evaluate specific results after the streets have been improved. If our requirements are not observed, we persuade the contractors to rectify the situation and reinstall water-intake grates whenever necessary.