The SAISC has compiled extensive minutes and a summary of the industry mobilization meeting held two weeks ago. We would appreciate your input as we will be developing the action plan over the next few weeks with the assistance of our CEO’s forum.
Many fabricators in business today require an easy-to-use bending solution that is affordable, and which will complement their existing cutting and welding facilities. To meet their requirements, First Cut principal Bystronic, a premier global provider of high-quality solutions for sheet metal processing businesses, has released the 100/3100, 160/3100 and 225/4100 models of their Xact Smart press brake range in South Africa.
Locally, First Cut, the leading local distributor of cutting consumables and capital equipment, distributes the full range of Bystronic capital equipment.
In terms of bending force, the 100/3100 model will exert 100 tons/1600 kN, the 160/3100 160 tons/1600 kN, and the 225/4100 model 225 tons/2250 kN. The 100/3100 and the 160/3100 offer bending lengths of 3100mm while the 225/4100 model has a 4100mm bending length. The standard stroke for all three machines is 200 mm and each has an open height of 480mm.
Options of extending the daylight and stroke by 100mm to an open height of 580 mm are also available on all three models.
Other features of these press brakes are an intuitive user interface; LED work-space lighting; Energy Saver; Fast Bend increased speed as well as options of two, four or five-axis back gauge, hydraulic tool clamping and most importantly a laser safety system.
In terms of the user interface, with the use of Bystronic’s BySoft 7 CAD/CAM software, it is possible to design parts, create cutting plans and bending programmes. When manufacturing, it is possible to monitor the production process. In spite of the power of Bystronic’s BySoft software, it is user-friendly and easy to operate. Moreover, this software package will integrate Xact Smart press brakes with other ‘smart’ machines in a factory operating environment.
Bystronic press brake operators are invited to use the Bystronic Bend Solver application for the calculation of all bending parameters. The Bend Solver illustrates the complex calculations using easily understandable visualisations. Depending on the material and its thickness, it provides the information about the required bending force, box height, upper tool height, the lower tool opening, the radius, and the minimum flange length. In addition, should a manufacturing facility have a number of Bystronic press brakes of varying capacities, it is possible to establish which bending machine will be most suitable for the job in hand.
For operators, interface with an Xact Smart press brake is through an intuitive touch-screen.
When bending steel parts, consistent accuracy is absolutely vital. Bystronic’s Xact Smart press brakes offer the highest levels of repetitive accuracy of any press brake on the market.
Bystronic also offers a comprehensive range of tools that will cover nearly every conceivable bending application. These tools will fit a range of clamping systems, while the hydraulic clamping of tools allows for rapid changes leading to greater productivity. Bystronic tools offer outstanding quality and a long service life thanks to manufacture using high-strength tempered 42CrMo4 steel, with deep inductive hardening to between 58 and 62 HRC.
In a busy production environment, it is still possible to keep track of tools as the most important information is engraved on the surface of the tool. However, should a custom tool be needed for a special application, Bystronic and First Cut will be happy to have such a tool designed and manufactured and delivered quickly and reliably.
Users of Xact Smart press brakes will benefit from decades of expert product design and knowledge in the processing of sheet steel. With advanced fiber lasers for ever-faster fabrication, complementary Xact Smart press brakes provide all the speed and versatility required for bending solutions within the high-speed automated ‘Industry 4.0’ environment which characterises manufacturing today.
In spite of the prevailing economic challenges industry has experienced in the past few years, First Cut has embarked upon a major expansion of its offices in Benrose, Johannesburg.
First Cut was ready for growth in the business and required additional floor space to cope with the growth and increased activity the company has been experiencing.
“We needed to expand our stores and to expand our footprint across all divisions. For example, we decided to renovate our showroom area for capital equipment from our international principals such as Starrett, Eclipse, Bystronic, Kanefusa and Everising.
And, on the consumables side of the business, particularly now that we are bringing in our principal Starrett’s DIY range of products, we need more space for a larger storage area,” explains Gary Willis, Director at First Cut responsible for the consumables division.
“For example, with increasing demand for the Starrett M1 oil spray aerosols, we will need this space so we can keep sufficient stock of this product as required,” he adds.
“In addition, we have made more room for technicians and members of its capital equipment team on the newly constructed mezzanine floor next to the main offices,” he explains, adding that they have also redesigned and reorganised the internal sales office. “With this office what is important is that there is room for growth as there is space for more people if required,” he continues.
The company started this expansion in mid-2017 and it is currently close to completion. “While we still need to fit air conditioning and complete the small finishing details, the changes we have made will go a long way to facilitating growth and also – very importantly – an improved service to our valued capital equipment and consumables customers,” Willis notes.
First Cut now has eight delivery vehicles, each allocated to its own collection bay. So now from the manufacturing facility, deliveries go down a chute, directly to the dispatch bays where security checks them. And with separate bays for each geographic area – for example, one for Randburg, one for Pretoria and so on – this has had a positive ‘knock-on’ effect in terms of service efficiencies and on-time deliveries to customers.
This major logistical improvement has led to improved customer relationships. “Naturally, the ultimate aim of course is to facilitate growth, improved customer relationships and service, and in so doing, the long-term profitability and sustainability of the company,” says Willis.
In terms of specific benefits to First Cut customers, Willis says this will result in an improved and quicker service and better stock availability. As an added bonus, a more comfortable working environment with more space has also been good for staff morale.
“For example, we can now carry out a stock-take with plenty of space. From the upstairs offices, it is also now possible to access the stores through a new doorway; and so the overall physical workflow and ergonomics in the new building are really great,” he elaborates.
Throughout the history of First Cut, there have been certain points in time where important strategic decisions have been made, which have had the effect of taking the business to the next level.
For example, the decision to move into capital equipment sales was one of these. First Cut’s current growth and expansion products project is also one of these milestone inflection points.
“The added and improved space is going to allow us to work more efficiently which, in turn, is sure to result in increased customer satisfaction,” Willis concludes.
When it comes to quality, reliability and safety, companies responsible for supplying the nation with power cannot afford to make mistakes. That is why Vital Engineering, a long-established manufacturer of gratings, stair treads, expanded metals, pressed floors and safety handrail, was selected to supply 500 000 Vitaclamps as part of the largest gratings, handrail and stair tread supply contract in Africa.
The contract included the supply of 250 000 Vitaclamps to Medupi Power Station in the Limpopo Province and 250 000 to Kusile Power Station in Mpumalanga. As part of the project, Vital Engineering also supplied some 200 000 m2 of grating panels and 70 km of handrailing and 8 000 stair treads.
“After carefully assessing the quality and durability of our products, our superior fixing product was chosen because it suited the client’s particular requirements and application,” explains Glen Pringle, Technical Director of Vital Engineering. “Their decision shows that the market recognises our products as synonymous with high quality, performance and safety.”
Vitaclamps are a patented, top-fixing grating panel unit intended to save installation time and costs, by improving installation turnaround times, reducing scaffold hire and improving overall operational safety in the mining, petrochemical and other industries.
“Vitaclamps reduce costs while improving safety, by enabling a unit to be tightened from the top – unlike the traditional clip on the market which is fixed underneath,” explains Pringle.
As always, safety was a key aspect in both the Eskom power station projects. Vital Engineering worked proactively with the principal contractor, MHPSA (Mitsubishi Hitachi Power Systems Africa) to meet and surpass specified quality and safety goals.
As a strong advocate in the industry of the importance of making an informed choice when it comes to safety products, Vital Engineering is wary of the number of sub-standard products that are ‘passed off’ as being equivalent to specified products by engineers or quantity surveyors. In comparison with other products on the market – including copies – Vitaclamps are:
- Stronger: They can more securely and reliably fix grating panels/flooring to the steelwork for various applications.
- Faster: They enable quicker fixing, easier maintenance and replacement of floor gratings.
- Safer: In addition to the use of friction grip nuts for improved safety, they are more visible for safety checks and can even be colour-coded.
- Easier to use: With better grip features and torque when tightening, they are simple and easy to fit.
The three Vitaclamp ranges — light, medium and heavy — are suitable for various applications and environments within mines, petrochemical plants and other on other industrial sites.
Vitaclamps are furthermore branded with the Vitagrid trademark — a sign of quality indicating a product is manufactured by an original equipment manufacturer (OEM).
“For example, when mining and petrochemical companies use products with this quality trademark, they protect themselves from risks associated with the use of poor quality copies available from other companies,” says Pringle.
He adds that Vitaclamps are an example of how the company continues to develop and produce innovative fixing solutions. With a proud history and track record of product innovation, Vital was the first square grating manufacturer on the market.
“We also manufactured the first ball-type handrail in both tubular and solid forged handrails; and m the first serrated gratings and expanded metal conveyor walkways to reduce slippage.
In addition, we have recently launched a distinctive channel clip, which clips onto the underside of the channel for faster installation,” he adds.
“We see a constant demand for our fixing products. In addition to utilising our products for their maintenance-related requirements, clients are even using them to secure opposition products in place. This is the result of the market’s growing preference for improved safety in industries ranging from power generation, mining, and petrochemicals to commercial, food and beverage, and materials handling sectors.”
In most if not all cases, Vitaclamps are sold with Vitagrid precision-made grating products and handrails.
“We do find that demand for these and many of our other patented gratings, stair treads, pressed floors and safety handrails products within South Africa – and from the international market – is growing, thanks to their innovative design and safety features. Vitaclamps are a really excellent example thereof, as their selection at some of our country’s leading power stations signifies,” Pringle concludes.
All producers of colour-coated coil offer a standard range of colours the names of which may be unique to the producer mill or generic such as red, blue, yellow, listed in a national standard e.g. SANS 1091 or other internationally recognised standards such as RAL and Pantone. Most producers that offer warrantees/guarantees against branded or trademarked products use names exclusive to their brands as a means to differentiate their coating systems from those of competitors, albeit the same colour. In the past consumers could specify a colour and expect to receive a particular coating system.
Regrettably, there are a number of unscrupulous profilers who import coil with a different, invariably inferior, coating system, but with colours matching the trademarked products and then selling them into the market using the same colour names. Unsuspecting consumers only discover the subterfuge when the coating ages or fails prematurely and that the coating system supplied carries no warranty.
Fortunately, some producer mills have previously trademark registered the names of their colours and have begun instituting infringement proceedings against the perpetrators.
In order to ensure you are getting the coating system you require we recommend that you specify the trademarked system plus the related colour when purchasing colour-coated cladding. Furthermore insist on a written warrantee or guarantee issued by the coil producing mill.
Please visit our website www.samcra.co.za for other articles and papers on subjects pertaining to cladding.
By Caroli Geldenhuys & *Richard Walls (Pr. Eng.), Stellenbosch University, Dept. of Civil Engineering, Fire Engineering Research Group.
Passive protection such as intumescent paints, vermiculite boards, and spray-on products can be very expensive. Thus, rational structural fire design methods, as presented here, can lead to significant savings. This article presents a brief introduction to a design method, the Slab Panel Method (SPM), which allows engineers to design composite floors for fire.
Believe it or not, when you set fire to a composite steel and concrete floor it just doesn’t want to fall over. It heats up to hundreds of degrees Celsius, beams buckle, floors sag, concrete can crack – but floors don’t collapse because they become giant hanging catenaries. Using results from full-scale
tests this behavior can now be modeled and designed for, potentially leading to significant savings in the cost of passive fire protection on steelwork – with as much as 40-50% of floor beams not needing protection (see Figure 1). Passive protection such as intumescent paints, vermiculite boards, and spray-on products can be very expensive. Thus, rational structural fire design methods, as presented here, can lead to significant savings. This article presents a brief introduction to a design method, the Slab Panel Method (SPM), which allows engineers to design composite floors for fire.
Overview of the Method
The Slab Panel Method is a structural fire design method used for composite steel and concrete floors in severe fires. Certain steelwork can reach above 850°C in the design, but the system still remains structurally sound. The method was developed by Prof Charles Clifton in New Zealand.
See the report R4-131:2006 for complete details regarding calculations. His work was originally based on the results of the famous full-scale fire tests done at Cardington by the BRE (Building Research Establishment), and the tensile membrane work by Prof Colin Bailey. Since then the SPM has been developed based on numerous other research projects as well. Figure 2 shows the eight-storey composite steel and lightweight concrete building used at Cardington, where various parts of the building were progressively exposed to severe fires and the overall structural behaviour studied.
The SPM procedure incorporates the reserve strength from a floor system under deformation in a fully developed fire. It is an ultimate limit state design procedure in some ways similar to building design for response to earthquakes, in that certain degrees of structural damage are permitted provided that collapse is prevented, but damage may occur in very severe fires.
How the SPM Works
The SPM design model is based on using yielding-moment action and tensile
membrane enhancement. The procedure is applied to large regions of a floor, known as slab panels, and incorporates the inelastic response of slabs (i.e. floors bend and sag permanently). At ambient temperatures the way loads are transmitted through a composite steel building involves:
The slab -> secondary beams -> primary beams -> columns.
When severe fire conditions occur and the interior secondary beams are unprotected, they lose most of their strength and the load path above cannot be maintained. The beams form plastic hinges and the load-carrying mechanism changes to a two-way spanning system, as illustrated by Figure 3. Here the load carrying path becomes:
The slab panel -> primary supporting beams – > columns.
From this, it can be seen that the secondary beams no longer play a major role, and simply form part of the sagging slab panel system. Hence, they do not need to be passively protected. However, it is essential that primary beams are protected as these carry the sagging slab panels.
The SPM theory is based on membrane action which is caused by in-plane forces within the slab. This allows the composite floor slab to bridge over the unprotected beams. This basically means that the rebar in the concrete slab, and the remaining secondary beams’ capacity, allow floors to hang from where support can be found, even when steelwork has failed. Figure 4 shows displacements of the beams that occurred during the fire tests at Cardington. It can be seen that no structural collapse occurred, even though significant deformation has occurred. It is interesting to note that the structure shown in Figure 4 had no passive protection whatsoever, experienced temperatures of over 1000°C, should have failed according to any standard design codes and yet did not collapse.
Under ultimate load conditions at ambient temperature, yield-line behaviour develops first and then tensile membrane enhancement, which occurs as the plastic hinges form. But under severe fire conditions, tensile membrane enhancement occurs first – i.e. the floor capacity increases as it becomes a hanging catenary. In the event of a fully developed fire, the SPM performs as follows:
1. The slab and the unprotected secondary beams may undergo considerable permanent deformation.
2. The primary support beams and columns undergo much less permanent
deformation compared to that within the panel.
3. The load-carrying capacity and the integrity of the floor system are preserved.
4. Both local and global collapse are prevented.
5. The development of the failure patterns in a slab panel is shown in Figure 5. The design equations are based on the final lay-out shown in Behaviour Mode (iv), as also seen in Figure 3.
After a severe fire secondary beams may potentially need to be repaired or replaced. However, very severe fires cause such significant damage, that everything in the building would probably have been destroyed. Recently a structure designed according to the SPM experienced a fire, and the structure survived with almost negligible damage. It is understood that the cost of the damage to the contents far exceeded the cost of the damage to the structure.
Software for the SPM
The Heavy Engineering Research Association of New Zealand has developed software to do the numerous calculations required to carry out SPM designs. This can now be purchased from Steel Construction NZ. Alternatively, similar free software that could also be used for this purpose is MACS+ from ArcelorMittal, or TSLAB from the SCI in the UK. Stellenbosch University is currently using the SPM software for research purposes.
Note: before using any of the above software make sure that you read and understand the design theory and methodologies. Rebar and certain detailing requirements are essential for the use of these methods, and the SPM guidelines provide good information regarding this.
The SPM and fire design in South Africa
SANS 10400 – Part T states that rational fire design in South Africa may be used provided that it achieves the same level of safety as implied by the document. These rational designs must be in accordance with BS 7974, which further states that competent persons must demonstrate that due diligence has been applied during the design process and the approving authorities can assess that due diligence has been applied. This basically means that under the auspices of rational design methods such as the SPM could be applied safely and according to SA code requirements (but it is important to discuss this with your local fire chief and fire engineers).
A recent project at Stellenbosch University (Geldenhuys, 2014) sought to calibrate the SPM to suit local South African conditions. It was shown that the SPM can be used as is, with only minor adjustments where New Zealand’s fire loading code is included. For more information on structural fire engineering principles and design you can contact the *corresponding author at Stellenbosch University’s fire engineering research group.
South Africa will soon have additional fire design principles and methods available in the updated SANS 10162-1 structural steel code. The recommendations presented in the Canadian CSA S16 code will be adopted, making fire design available to local engineers in the near future. More details to follow soon…
Lessons from Spencer’s Voortman visit – Part II
By Spencer Erling, Education Director, SAISC
Voortman recently invited and paid for Spencer’s travel costs to visit their factory in Holland as well as a Dutch fabricator and a German fabricator. This is the second of a series of three articles to share my findings with our members. The SAISC’s grateful thanks go out to the Voortman team and their SA representative First Cut for making this eye opening trip possible. In this article we look at entry level equipment on offer from Voortman. Look out for our next article in Steel Construction No. 3 for 2015 where we will be writing up about the more sophisticated equipment from the Voortman range.
It does sound a bit crazy to say and think that I was going to Holland to find out about the Voortman range of equipment and this would happen in only about one and a half days on site for the whole range. Just how could it be possible?
Even more so when I think back to 1979 when I first went to Germany to purchase Peddinghaus equipment. We planned on a four-day visit to see just their two models of drill line NC machines but this required visits to factories all around the western side of West Germany even venturing into Holland to Ulft and in passing see some of the punching equipment that Peddinghaus was synonymous with in those days.
So how could it be possible to see Voortmans’ vast range of equipment in such a short time? The answer is actually quite simple. Voortman has a strong marketing set-up geared to doing just this. At the heart of the programme is their Experience Centre in which all of their equipment is set up to show and explain their capabilities under one roof. One of the treats for me at their centre is this delightful staircase (see opposite page).
Add to this, they have their own structural steel fabrication shop on site which is a great proving ground for their equipment as well as their production and assembly lines for machines on order. This department is the epitome of European discipline and organisation. Their parts stock control is very sophisticated, computer controlled and items are all automatically withdrawn from their bins and placed into holding bins by order number.
And then finally within an hour and a bit from the centre, there are two very competent fabricators, one sporting a brand new works with an extensive range of Voortman equipment the other having equipment that has been in use for some time now.
What more could one ask for to get to know their range of equipment quickly, efficiently and without fuss? Well done on that score to the Voortman team. It is a few years since I visited the Kaltenbach bi-annual factory based exhibition or the North American Steel Constructtion Conference where many manufacturers show off their equipment, the modern facilities and whole Voortman approach is startlingly refreshing and clearly a winner.
Entry level equipment
Voortman’s approach to software
It is interesting to note that Voortman has developed a software system under the name of VACAM which is used to control the whole range of their machines and handling systems. Apart from the basic common sense that this approach makes, adding new machines or handling equipment to existing facilities becomes, relatively speaking, an easy exercise. Voortman has a team of 15 programmers who are experts at doing just that.
I guess for the small to small-medium fabricator the thought of increasing productivity by purchasing CNC equipment is a daunting concept (especially for those of you who have not done any ‘what if’ assessments of the equipment).
In the article published in Steel Construction No. 6 2014, Chasing profitability for the small to medium steel fabricator, Danny Steyn writes about just how important it is if you want to survive in these tight financial times (and even better – prosper), you must take the plunge and get on the ladder to the future by starting with some CNC equipment. And before going much further let’s throw some numbers at you. Consider the following proposal:
Consider a fabricating company is doing say 100 tons per month for 11 months a year. Sadly, due to competition laws, I really do not know what an hour costs in a workshop these days but I am sure that very few of you get away with less than R450.00 per hour.
If you were to save just five hours per ton this works out at a pot of money close to R2.5 million. So in two or three years there is a good chance you will be able to pay off between one and two entry level models. If you do everything manually i.e. sawing, cutting, marking, drilling and the like, saving five hours per ton with a couple of machines is very realistic and probably quite conservative. Just consider how much overheads you can save by your 3D TEKLA package speaking directly to your NC machines.
Can you afford not to be going the route?
Of course the definition of an hour is important here. In my estimating course I teach that the hour that you should be working on is the hours actually recorded to a job, so excluding labourers, grinders, despatch and the like whose costs would be added to the recorded hours. In addition each hour attracts a portion of the company overheads.
If you do not know about these things maybe you should consider doing the SAISC estimating course.
Which machines are available at entry level from Voortman?
You will be pleasantly surprised just what can be found for realistic prices. Somehow everyone automatically seems to start by thinking about a beam drill line. Even before looking at the models available, learn from the experience of those who have already gone the route. On more than one occasion I have been told “had I known what I know now, I would have started with a plate processing machine before a beam drilling machine – of all my NC machines it is the plate processing that works two shifts to keep up with the demand”. Think about it!
Right at the bottom in its simplest form is the V600. Having only one horizontal drill head it is necessary to turn the beam to enable drilling, slotting and marking to the flanges and the web. To ensure accuracy of holing on each of the three faces, each time the beam is turned by the machine zero is identified for the new face of the steel to be drilled using laser. The drill head moves along the length of the steel.
As with all their drilling equipment, high speed carbide drilling is available (which is dramatically faster than high speed drill bits), as well as the automatic tool changer with five stations (including tapping up to 30mm
diameter, centre point marking and counter sinking) capable of up to 40mm diameter holes.
Next step up is the V613/1000 (the 1000 indicating
nominal maximum width of beam. The actual width maximum is 1050).
Here the big difference when compared with the V600 is that the single drilling head rotates to suit the flanges and the web i.e. two horizontal and one vertical position and the steel passes through the machine compared with the V600 where the machine travels along the length of steel.
In addition to the drilling capabilities mentioned for the V600 it has 2 x 5 station tool changers. Optional extras include layout marking (i.e. where attachments need to be assembled) and numbering marking for part identification, feeder truck or roller feed measuring systems.
We will look at the full beam drilling capability of the V630 machines in the next article.
Beam sawing machines
Unless your business is based on cut-to-size ordering from service centres, one should not think in terms of standalone drilling machines but rather linking them into a sawing machine station
Thinking along the lines as above, if buying cut-to-size is costing you between 5 and 10% of the basic steel price it does not take rocket science to calculate that to pay off a saw does not need too many tons per month, but do not forget to ask about the cost of replacing the band saw blades which can be quite often for heavily working saws.
The Voortman range of band saws all have the VB description followed by the nominal maximum width capability (VB750, 1050, 1250)
All are mounted on rotating turn tables for any angle of cut, have hydraulic blade tensioners and guides either side of the beam to be cut by width; to keep the cut square and have the options of length stop, roller feed or truck length measuring systems.
One of the items that was a first for me was their “short piece removal” clamping system (useful for short beams or scrap removal). It is also possible to program the machine to return longer length off-cuts back to the stock yard. This works very well for lightly loaded saws as it is quite time consuming.
The great thing is that when you buy from Voortman they will work through your planning requirements and in the case of a saw/ beam drill combo it is possible to have just one operator for the two machines. Layout and movement are designed to minimise handling.
By Spencer Erling, Education Director, SAISC
It is just three and a half years since the first article in the series was written, (see Volume 35 No. 2 2011, Some gems from Spencer’s Steel Enlightenment Course for Wits students), a whole bunch of courses later we have enough material for a follow up article. Our grateful thanks goes out to our “innovative but somewhat misguided students” usually in the form of (incorrect) answers to test papers
The courses are usually offered in the last week of the student’s vacation, either at year end or mid-year breaks. You would think that some of the students were working under extreme pressure or round the clock before attending the program (during vacation huh?) but more likely extreme partying because some of them walk in (quite often late) sit down and fall asleep even before they have to listen to one word of my, apparently to them at least, boring subject and delivery.
So it is no surprise that we do get the really garbage answers to straight forward questions from some of our not so good candidates. Of course as the lecturer you begin to question yourself and your (in) ability to get the message across… fortunately with experience you learn who these wonderful answers are coming from and can ignore their poor, sleep driven, performance.
The course is an attempt to introduce second year civil engineering students to the whole structural steel process literally from digging iron ore out of the ground to handing over the proverbial front door key. Part of the course is dedicated to field visits to tube makers, fabricators and to erection sites. Some of the questions are aimed at finding out if they have learnt something from these visits in addition to the lectures. All of the questions are straight forward multiple choice or one line answer type. There are no trick questions but we would like to know if the students can think broadly enough to “join some of the dots”
New welding theories
We spend a good two hours covering weld
processes, types (fillet / groove), sizes, positions (flat, vertical up etc), defects and
how to find those defects (NDT) but the
emphasis is on the fact that we use either
flux around or in the rod to create a gas
shield to keep the nasty’s in the air away
from the molten pool (SMAW or FCAW) or
we deliver a gas shield to point of welding
Upon being asked a question to which we would expect an answer along the lines just described some of the proposed new methods would be (sic)
• The use of Airtight welders (a pity about his need to breath…)
• Use a gun which has the ability to remove the gases from the welding pool (should we try a 45 magnum…???)
• Using a (paint) primer or other protective (paint protective to welding?) coating
• Submerging in water… and along similar lines
• Add water to the weld (to cool off the heat/ melt) (now that should keep the welder guessing just who in the process has gone crazy)
When asked to describe some common weld defects (expecting an answer like cracks, lack of fusion, shape and or size of the weld, distortion) the latest defect is…
• Ingots (yup I guess an ingot could do some real damage to a weld…)
When asked to explain how the welding up of tubes along their length in a tube mill differs from normal (SMAW, GMAW, FCAW, SAW) methods we expect an answer along the lines that induction welding using heat and pressure only and no filler wire is used in tube mills. Tube makers here is new one for you to try (sic)
• The hollow section is fed with carbon from within the tube and melted by heated arc to form the weld
Yes we all know there a lots and lots of issues around bolts, bolt grades, new bolt specifications and, and, and of course tightening of bolts correctly. The SAISC has for a long time now followed North American methods of tightening HSFG and other preloaded bolts (rather than the torqueing methods adopted by European specifications). Clearly this is an important subject and receives it fair share during the (limited) time available. The turn of the nut method is described carefully and emphasised several times. So sure, one of the questions is to describe the method.
Now pay attention all of you involved in the process of pre-loading bolts. Stop wasting your time and energy you can just (sic)
• Weld the HSFG nuts
Fire protection issues
Why we need to passively fire protect steel and how we do it is the subject of one of the talks. The reason why is ascribed to the fact that at 600°C temperatures steel has lost 70% of it’s yield strength, something that usually leads to collapse. One of my favourite questions is why we passively protect our steel expecting the above explanation as an answer.
Readers in the opinion of one of our budding geniuses we have our theory totally wrong because (sic)
• The greater / higher the temperature degree, the higher the yield strength of steel.
We have been missing out on some readily easy to apply materials for passive fire protection. The latest suggestions are…
• Using a layer of copper around the structure since copper is a bad conductor of heat
And the winner by far…
• Galvanizing and mixing it with alloy to make it more brittle (shoo! I am clearly confusing them… must remember to try not to confuse them so much in future)
Some time is spent on the fact that steel rusts and that we need to prepare the steel suitably removing rust and other not desirables (i.e. wire brush, shot blast, acid dip etc) to receive paint, the role of prime coats etc.
We have lost out on a very common building material to assist with rust removal
• Concrete encasement
Metallurgists who might read these words of wisdom, did you know that the new role for prime paint is (sic)
• To get to know the quality of the steel
Naturally any good course on the structural steel process will cover how we enclose our structures (clad) and we cover metal, fibre cement, precast elements, glass and high density polystyrene (LSFB) methods but sadly we have been missing out on two readily available products (with apologies to our recycling industry…)
• Recycled cans
• Motor cars
Steel and concrete interfacing
Finally the course covers the interface between steel structures and concrete foundations and the need to create the ability to adjust the steelwork to suit the (often) incorrect holding down bolts. I emphasise the need for our steel to be adjustable. That is the answer I expect to the question I have occasionally set.
They get full marks for the one word “adjustment”
The following treatise received no marks… but does highlight how easily the students can confuse and mix the different parts of the course (sic)
• Transferring the loads through the base plate into the foundation by a method that wont allow the bolts and the base plate to easily corrode the concrete and create spaces in these connections. Adding a flux between the plate and concrete can do a lot to spread the load uniformly (at a guess he meant grout not flux…)
Finally a serious word of warning, do not apply or use any of the above theories or methods without extensive research and testing which I think would be a whole waste of time and effort. If you do, it is at your own risk.