Drainage manager software User story
Taken from an NRG Drainage manager software users true account. After using the software to create accurate drainage design and setting out drawings. Along with manhole, gulley and pipe schedules, quantities and extensive list of common drainage calculations.
Drainage setting out is quite simple, provided that the manholes are scheduled correctly, but this is where simplicity ends.
Several factors have to be taken into account when setting out the pipes, such as road curvature, clashes with ducts, existing services, culverts, cross drains, connections to gullies, and of course the earthworks.
Once the setting out is sorted, the next stage is to order the pipes and manhole components. Drainage shopping lists are never straightforward. So many factors can influence and affect the quantities required when calculating pipes, connectors, sealing rings, pipe grease, junctions, gully pipe, gully pots, gully lids, manhole rings in a variety of sizes and diameters, step irons, cover slabs, bricks, cement, manhole lids, bedding stone and concrete.
When the list is complete, you then have to order it, find somewhere to store it all safely as near to the works as possible and then direct the drainage contractor to start installation.
In charge of the drainage
As an Engineer on a recent highway/bypass build project that was a few months old when I started, having already suffering some delays. The roadwork’s agent gave me an office and a brief “You can be in charge of the drainage”. My heart sank, I cant say I have ever enjoyed drainage but “Be professional!” I thought and I gladly accepted the challenge.
Having used NRG Survey Software for several years and knowing some of the software modules well, I set to work hatching my plan for the “easy option” to get the job done as easy and quickly as possible. I decided my plan would involve using the NRG Drainage Manager software. I had not previously used the NRG Drainage Manager software on any live project so now was the perfect opportunity to see what it can do.
After going over a set of drawings, a book of drainage schedules, and a copy of Appendix 5. I was armed and ready to get started. After getting answers to a few queries regarding manhole offsets, I set about entering the drainage schedules into the Drainage Manager software.
Easily calculate manhole positions
First to be entered into the software were the manholes: Enter manhole name, Enter chainage and offset from edge of carriageway, (Using the MOSS model within Drainage Manager, I could easily calculate these positions). Select manhole type from the standard detail list. Enter outfall pipe invert level. Enter cover level. Get existing ground level from the original ground survey. Next Manhole. Each one took less than a minute. I got to the end of the manhole schedule for the first network. I sat back and admired my handywork on the screen with the road alignment sweeping through the view port, and my manholes spaced along the edges, with their names printed neatly by each dot. Beautiful. It was time for lunch.
I then started entering the details from the pipes schedule. After clicking the “Add pipe” button in the toolbar and then clicking from one manhole to the next. The input screen shows up. The software had calculated all the invert levels from the manhole details I had inputted. All I then had to do was check the inverts matched the schedule, making a note that the upstream invert level should always be the same as the outfall pipe of the upstream manhole.
Select the pipe type
Next I selected the pipe type, carrier drain, filter drain, fin drain etc. and then the diameter. With a quick glance at the appendix 5 design groups I selected the bedding type from the standard detail list. Having got the existing levels from the original ground survey and the finished levels from the design strings exported, previously, from MOSS. The next trick was to correct the pipe length.
Almost all drainage schedules quote pipe length “as the crow flies”, what they don’t take into account slope length, extra pipe within the manhole and curvature around external radii of the road. If you order pipe lengths based solely on the schedules you could end up with too much or too little pipe, both costly. As it happens my first pipe was on the outside of a tight right hand bend so I selected the option to align the pipe with the road. This avoids the pipe cutting the corner and being constructed under the carriageway.
Calculate Pipe length
I then selected the Calculate Pipe length tool. The pipe had gained in length by up to 1m. Not much, but a pipe 1m short on site would definately cause a costly delay. Crisis avoided, I started entering the gully positions. These, unfortunately, had to be scaled off from the drawings, however I only needed to scale the chainage, so I created a list – gullies on the left and gullies on the right. I selected the pipe that my first gully came off. Then using the Drainage Manager software Connections editor entered the pot position by chainage at the edge of the carriageway, the gully type from the standard detail list, then the junction diameter and angle to the pipe. The system calculated the invert level for me at the pipe and at the pot. So now on to the next gully.
I entered the last gully and finished for the day having entered the complete schedule for the first network. Not a bad days work even if I do say so myself.
The next morning I had enough information to start setting out the pipes, manholes and gully junctions.
I logged into NRG Surveys on my pc0 and launched the Drainage Manager software. After loading the previous days file, I set about printing the pipe setting out sheets with coordinates for all the pegs at a 3m offset from the pipe, suggested traveller heights, and invert levels. I then gave these to the setting out engineer who was rather happy because he didn’t really have to do much before getting started.
Drainage components database
Happy that I had avoided the prospect of going out in the rain with the setting out engineer. I the set about putting the order together for the materials needed to build the drainage network. To do this I acquired a copy of the purchase orders. I knew from the orders which products we were using, so I borrowed the supplier catalogues from the roadwork’s agent and with a quick menu choice “Stock, Edit components” I was into the extensive Drainage Manager software components database. Here there is a list of all of the components you require to build the drains. The list is broken down into component categories: pipes, rings, covers, cover slabs, bedding materials etc. For each component there is a type and its associated sizes laid out in a nice, easy to use table.
Pipe (component); UPVC Twinwall (type); 0.6m diameter, 6m long, 0.037m thickness (size)
I set about adding the pipes, manhole rings, along with the other materials we would use to the already extensive, list. Once happy with the list of components, I then proceeded to edit the defaults for the manholes and pipes. Within the defaults I can select what the default products to be used are. I didn’t have to enter any sizes, just the type.
I knew from several pieces of contract documentation, plus a query to the client, that we would use UPVC Twinwall pipe. So I set all pipe trench types from the standard detail list to UPVC Twinwall. After consulting the design groups in appendix 5. I knew that all carrier drains were to be trench type “S”. I left the bedding and surround items blank in the defaults because we would use different grades of material depending on the diameter, I would set these later. For the manholes I selected Stepped Rings, Cover slabs and covers and for the deeper chambers, reducing slabs, landing slabs, and shafts were added.
I was now set up to start “constructing” the manholes and pipes within the NRG Drainage Manager software.
Calculate the ring depths
To do the Manholes, I opened up the manhole editor, then for each manhole selected “Edit Components”. From here I could calculate the ring depths for each manhole. The system, using the Components database, would calculate the rings required. Upon opening the first manhole, the cover slab, cover, and type of rings to be used were already shown due to the defaults I set earlier.
The overall depth of the manhole was also calculated atomatically by the software. Before calculating the ring depth, I checked the make-up default for the brickwork. The covers we were using were 100mm thick. The standard detail requires 225-375mm for bricks and cover, so I set the defaults to 125 min and 275 max.
At first, I clicked the “Calculate” button to get the ring depth and it gave me the ring depth and a selection of ring sizes to use but I had not taken into account the pipe diameters and the benching below the rings. So to allow for this there is a setting in Drainage Manager called “Depth from Invert to First Ring”, this is the depth from the outfall pipe to the crown of the highest inlet, plus approximately 50mm for benching. Back to the schedule, I calculated the depth using basic arithmetic (I’m glad I paid attention in primary school!) and entered the depth. I then clicked calculate for a 750mm deep ring and I was now on my way to go shopping.
Increase benching to acquire depth
After four or five manholes were entered, I came across a problem. The design levels were incapable of constructing a manhole to specification! due to “Can’t fit ring depths, try adjusting defaults” message on screen. I kept my cool and started adding to the “depth to first ring”. In practice this is the equivalent of increasing the benching to acquire depth and it took 20mm extra…. Easy!
The pipes posed fewer problems. Firstly, the Drainage Manager “Edit Components” option, I had the pipe type already selected, plus diameter. For the bedding materials, it took more ingenuity and knowledge of the Highway Specifications. I trawled the offices for a copy of the “White Book” Volume 1 and 2. Locating one and after a brief re-read, with a cup of tea I was back in business.
I entered the materials as required. For each pipe I selected “Calculate Quantities”, a table of bedding and surround volumes plus the number of pipes required to order was then calculated and displayed on the screen. The gullies were just as simple to input and calculate.
After a couple of hours I had completed this exercise for the first network. One minute later I had printed off a stock list, the manhole sheets and the pipe sheets (sewer, or lollipop sheets). I was able to send the mareials orders to the suppliers with a few directions to delivery accesses, the second set was checked over with the schedule, and then issued to the setting out engineer and sub-contractor.
Keeping track of progress
As the contract progressed, changes were made to the design. These were easily added in Drainage Manager software by changing the details in the editor, literally a five-minute job. As we constructed the drains. For each run I could select “Built”, this then added the drain to the As-Built database, thus keeping track of progress and materials used.
The QS was quite happy with this as accurate monthly evaluations were given every “payday”. Once all the data had been entered, I could evaluate the requirements for the contract, making amendments to the purchase orders, which were short. I also gave a list to the crushing plant asking for the tonnages required for bedding. It also gave me the opportunity to check the design for construction problems.
Using a very clever tool I could check the whole design for clashes with other pipes. We had a few clashes over culverts that, during design approval, had increased in diameter. I could notify the designer forthwith. Towards the contract end, final measures were performed quite quickly within Drainage Manager and sub-contractor payments based upon it.
Most contract workers that I have met in my time, are of the opinion that drainage installation is very straightforward. I am starting to believe them, as long as you have the right software to do the hard stuff for you.
To dig a trench – use a digger, not a spoon.
To do drainage calculations – use a computer with NRG Drainage Manager – not pen and paper.
It really is that simple.