Greg would have a field day!
The last blog saw me having a few issues identifying the contract that was in place for the £1.2 million of waterproof membrane which we will be spraying in permanent works beginning on the 3rd Jun 14.. Turns out there wasn’t one…
I am determined not to use this blog to drip about the complete mismanagement of this process…I’m beginning to bore myself. So instead I will detail some of what I’ve learnt and try to tease out what John would call, ‘CPR gold’.
1. Statement of Requirement. The specification designed by the MottMacDonald Ltd is linked here. 16 Section KW20 Materials and Workmanship Specification – Spray Applied Waterproofing Membrane Systems for SCL Works
The performance requirements are at para KW20.1301, and Table KW20-03 in the appendix. In outline they pertain to bonding properties, permeability, crack bridging and flammability.
2. Preferred suppliers. In the beginning, 4 chemical materials companies were under consideration. I hesistate to use the term preferred suppliers, as there is a slight nuance here.
a. Subcontractors. Blokes doings things with kit and materials. The Joint Venture will invite subcontractors to tender for work, using this website. Designed for use at the Olympics, it has become industry standard for major capital contracts to ensure transparency. Subcontractors then accept the invite and are added to a list ahead of a commercial comparison, eventually leading to a subcontract, in this instance in the form of NEC.
b. Suppliers. Just stuff. A materials requisition report is raised from BFK and sent to a list of suppliers. This process is much less transparent and very much favours older, larger, richer and more established companies. It follows a process reliant on old contacts and who we have used before, combined with a quick Google search. We let them know we are looking, and suppliers then tender for the work, are compared, and a decision is made culminating in a supply order.
For the waterproof membrane, we are in a very grey area. In essence, we are ordering material alone, which should put us in point 2b territory. However, we are also hiring their machine to apply it AND getting a techical expert to train us. This training really should stray no further than the classroom, but he is already operating underground…applying the material in a trial tunnel…that is in fact going to be a cross passage…that will be inspected and signed off as permanent works. This strikes me as a professional service and one which should be protected by the assurances commensurate with a subcontract.
3. Commercial Comparison. The four chosen suppliers then underwent a commercial comparison, the output of which is here: Commercial Comparison. The churn of people in this place is such that the people that were involved have all left, so I have tried to pick out the decision making process (I’ve hidden the names to product their commercial modesty so if you’re having trouble sleeping, play along at home and see if you can work out who we went with.
a. Specification. Clearly, the first criteria test is if your product meets the spec.Although all state they can, one was unable to prove it. The eagle eyed will note than one actually does not meet the spec on permeability. His waterproofing is not waterproof which you would have thought would have harmed his chances…
b. Experience. Previous case studies are all important, and if you can say that your product has been used successfully on previous high profile projects, it will stand you in good stead. Additionally, the tunneling fraternity is quite small so it is likely that some of those making the decision will have worked on those jobs. Definitely the case here, and you will note on this critieria, one supplier is the clear winner.
c. Cost. I remember Greg saying that the cheapest and most expensive tenders are often stripped away straight off the bat. In this instance the most expensive is prohibitively so, and as such put himself out of the running. Although the original budget is lost in the mists of time, we are now looking at projected costs for this work for the purposes of the materials requistion.
d. Add Ons. In order to further mitigate risk, the supplier may offer supervsion, training WITH accredition and ongoing technical support. For us here, this is critical. There is very little knowledge on the product or the equipment.
How did you get on? Hopefully you all went with Supplier 3…BASF with MasterSeal 345… because we did and its too late now. The irony is however, we’d already signed up to the automated machine…the Logica….BASF owned which can only use the BASF products so it seems this process was slightly moot.
In other news,
Thermal Trials. The thermal imaging trial has rolled out on site this week. Feedback was positive, and having delivered a number of ‘toolbox talks’ it is reassuring to note that much like your average Sapper, the miners were really only interested in how expensive the kit was. I am awaiting data feedback, but check out this footage of the shotcrete being applied to the crown of a tunnel.
Note:
1. The shotcrete begins to react in the air immediately on leaving the nozzle. Note, the reaction as it accelerates when on the surface…its is easy to see the contrast with the cooler concrete, which will immediately identify concrete which is not curing and thus areas of risk
2. The rebound (waste) actually amounts to quite a bit. In the dust of the tunnel this is often not noticed to such an extent.
Rugger. I turned out for the Joint Venture v CrossRail(and ringers) at the hallowed turf of the Honourable Artillery Company ground in Moorgate. After some pretty fruity tackling interspersed with moments of sublime and ridiculous, we ground out a 10-5 victory. Check out the first 5 mins…you will note my slick hands, sublime running lines and stonewall tackling are mainly obsured by a fat bald bloke in a wifebeater.
Holdfast Training Services Trial Blog 
nice post – lots of info, unfortunately you tube isn’t accesible inside the wire so I’ll have to take your word for the the supreme quality of skill and atheleticism obscured by the fat bloke. I wouldn’t doubt it anyway. The other video clips I might even be sad enought to watch at home… Well Done!
Hi Richard…thanks very much. Worth checking out the thermal video(not so much the rugby!) as the footage has uncovered some other phenomena that I’d be keen to hear your ideas on, not least the amou t of wastage it seems to show.
The trial seems to be developing into a two stage “SOP”. Stage 1 is a confirmatory sweep, firstly to check the accelerating is dosing correctly and a secondly that the concrete is curing at the rate expected. The easy bit.
Stage 2 is the data collection in order to support a temp/ strength correlation. This is a bit more tricky as I’m finding the balance between getting a reliable amount of data in a consistent manner difficult to balance with the practicalities on site.
Ryan, an absoultely fantastic video. I’ll give the”men in shorts” one a miss though! The thermal imaging is interesting, certainly more interesting than the alst one I looked at which involved the sunshade of a tent for 48 hours!
Are you sure you didn’t fall into the same trap as those at the toolbox talks though? Certainly the contrast on the structure between “cold” and “hot” is easy to see, there’s a band of lower temperature that is consistent – what was actually done about that?
My reading of the reaction you describe as the shotcrete leaves the nozzle is a little different – it looks like what you are seeing is the mixing of 3 streams, warm water, cold air and cold dry mix, the periodic flare is more likely the point where the cement mix stops being delivered (a blockage perhaps) and warm water flows through unimpeded. Look back at the image and the shotcrete stream is normally towards the lower end of spectrum, indicating a good mix of the 3 constituents, the highest thermal signature is consistentt with that given off by the water pipe which causes peaks whenever it comes into view, what do you think?
Hello Hobbit! (sorry I’m not sure who this is!?)
Important to note firstly that this footage did not form part of the trialling, and has been generated in the initial two week ‘feedback’ period. I’ve rolled the cameras out to site with a checks set based on what I require but tempered with how they already do business on site. This is to allow a two week period ‘soft landing’ so we can iron out the issues ahead if the trial proper.
The first was the anomaly caused by getting the machine in the picture, noted and fed into the lads on site to avoid anything but the shotcrete.
You make an interesting point about the constituents of the shotcrete mix. I hadn’t looked at the spray in to much detail but it could be informative. I have data on concrete temp when it arrives on site (currently averaging 13 degrees) and we take an ambient temperature reading although water temp is a little more difficult to get. One phenomenon that has been prevalent is an interruption in flow of accelerant. A separate hose with a separate pump that has been problematic in the past. I had opted to test for this using the camera as the material hits the wall rather than at the nozzle. I have seen footage similar to this but when the accelerant is turned off mid flow….the contrast is easy to see. The footage was shot by Warwick Uni and I’ve asked for permission to use it.
You also highlight an important point on the sensitivity of the camera itself. The camera identifies the hottest and coldest points in picture, represents them as each end of the colour spectrum them spreads the rest of the colours between. This means that average temps can actually change colour as you move the cameras depending on hot/cold points in view. I’m looking at how I can use the still photography function to capture the image and correlate later? Keen to hear any ideas you may have to improve this?
Ryan, sorry for the confusion – its Mark ( the name is a reference back to teh heady old days of Denison Block!)
You may find that the camera software and firmware allows you to set the view to an absolute range rather than a relative range, potentially you lose some resolution but given the narrow band of tempertaures probably not enough to worry about, it would certainly help on site interpretation if that’s the goal, it would also avoid the odd operator droop that brings the machine and hose into sight.
The problem with stills will be taking the still at the right time, again the software with the camera may allow you to interrogate the images on a pc using the mouse as a cursor to get temperature reports.
The trial sounds quite interesting as a whole, what is the main driver? what are the aims?