O SlideShare utiliza cookies para otimizar a funcionalidade e o desempenho do site, assim como para apresentar publicidade mais relevante aos nossos usuários. Se você continuar a navegar o site, você aceita o uso de cookies. Leia nosso Contrato do Usuário e nossa Política de Privacidade.
O SlideShare utiliza cookies para otimizar a funcionalidade e o desempenho do site, assim como para apresentar publicidade mais relevante aos nossos usuários. Se você continuar a utilizar o site, você aceita o uso de cookies. Leia nossa Política de Privacidade e nosso Contrato do Usuário para obter mais detalhes.
Weekly Engineering Report #3
Darren Yee and Navil Smith
Week 3 at the B2 site started well with a visit to the factory, which was very helpful. In
addition the new tablets are proving to be invaluable and time saving. We have completed all of
our objectives from last week, and have decided to attempt to turn in a Midterm report next
week as it will be week 4. We aim to have compiled all of our data to that point into charts and
graphs, provide preliminary analysis, and speculate trends. There was data collected this week
for all 4 major mateline trades. A few brief changes to the format of the report this week, but
largely the same as last week.
Mateline work has seen an increase in productivity due to some of the trades finishing
with 1st floor/ corrective work (plumbing). Electrical matelines have moved swiftly and steadily in
the past week, completing 4 floors of connections in the past week. Carpenters have also
picked up productivity despite having the same number of personnel on site. Due to the variable
nature of these matelines, less data points are being observed. They are currently on the 9th
floor and will work their way down. Sprinklers completed one floor, and began testing floors
210. It should be noted that when the workers were performing testing, the main riser fell 4
inches vertically. The issue was beginning to be resolved today, but will most likely result in
delay of mateline work in the coming week. Lastly, plumbing work is underway for the first time
since we began observing. Data points have been collected and more observation will be
This week’s report is largely the same as last week. We have added the table below,
which is just a simple indicator of how much mateline work we feel has been completed in the
past week. In addition, we have removed PTAC installation as a subject upon learning that the
factory is now installing all units. The Mateline Procedure document is not submitted this week,
a more complete one will be submitted next week with the Midterm report.
High Moderate Low/ None
Carpenters, Electrical Sprinklers, Plumbing
● Support Failure of Sprinkler Riser
● Provided Wall Frames Not Being Utilized
● Grooved 1” Pipes
● Excessive Paint
Table of Contents
Current: Week 3
Future: Week 4
Qualitative and Empirical Data
Steampipe Mateline Work
Storm Pipe Mateline Work
Provided Wall Frames Not Being Utilized
Uneven Holes Around Steel Plates
Grooved 1” Pipes
Misalignment of Holes and Pipes on 13th Floor
Elbow Pipe out of wall
Support Failure of Sprinkler Riser
1.1. Long Term
The objective of this 8 week study is to observe processes and
complications on the B2 construction site that are unique to modular construction.
Quantitative and qualitative data will be gathered to ascertain trends in mateline
work. Studies will include time studies, logging of recurrence of incidents, photo
documentation, and compilation of worker feedback. Weekly reports will be
handed in to highlight immediate concerns and noticed trends. A final report will
be compiled with all data tabulated, graphed and analyzed.
1.2. Current: Week 3
The objective for this week was to continue to gather data points on
sprinkler, carpentry, electrical, and plumbing mateline work. At least one process
from each trade will be recorded into the separate mateline process document.
1.3. Future: Week 4
The objective for next week is to have enough information to create a
Midterm report, which will include charts and graphs, trend observations,
preliminary analysis, and will give us an idea of what other types of data may be
2.1. Time Studies
To gain a quantitative understanding of the labor required for various
mateline work, data points are gathered in time per mateline, number of workers,
and notes on time it takes to prep mateline work. In addition, more detailed data
that pertains to time may be collected, the nature of which will change by
mateline type. Considerations will be made for workers learning mateline work for
the first time to obtain a more accurate representation of typical time spent. Other
factors that may produce outliers will be noted as well.
2.2. Photo Documentation
Photos of specific incidents will be taken and referenced in the appendix.
This includes hardware problems, installation problems, access problems etc.
2.3. Qualitative and Empirical Data
Suggestions from workers will be recorded with photo documentation and
will be sorted into isolated or recurring incidents. Best judgement will be used to
choose which are immediate concerns that should be notified to the factory.
The format is designed for selective reading and brevity. Data points will
not be shown but a summary of the quality and quantity of data will be reported.
Comments on the data are included where necessary. The final report will have
all data points graphed and tabulated.
The first page will have a summary of the site work that was done that
week, the data points that were collected, and other pertinent information such as
updates to the reporting process. Important points will be listed as “Immediate
Attention” items. These are chosen to highlight some ways the factory can
consider changing procedures to make onsite mateline work and installation
A hyperlinked table of content is on the second and third pages.
Starting on the fourth page is the body of the report. The content of the
first two items “Objectives” and “Methodology” will largely remain static.
Detailed summary of all observations and data points collected are under
their respective subjects under “Matelines” or “Installation”. This is where most of
the weekly information is detailed. All pictures that are referenced will be
hyperlinked to the appendix, with hyperlinks back to the body for convenience.
Next is “Qualitative and Empirical Data” which is where we will put more
general observations including general feedback from workers, observed impacts
specific to modular construction, or efficiency trends.
There is a catchall section named “Other Issues or Events” to detail
important information on a week to week basis that does not necessarily pertain
to mateline work.
Finally in the “Conclusions and Recommendations” section, trends will be
stated and speculation will be offered from the report writers on ways to improve
The work has been going very smoothly and swiftly. All the module
electrical connections have been done from the 11th to the 7th floor. The worker
finished some previous unfinished work on floor 6. Once all the connections are
done upto the 2nd floor, the workers will be testing all the floors.
The testing of floor 2 was completed on Monday. Workers have been
doing the main electrical lines connections to the circuit breakers in floor 4 and
13. They are expected to finish this week.
According to the electrical foreman, it will take upto one week to do a
complete check of every floor up to the 11th floor, thus a period of 11 weeks to
complete with the 11 floors.
The task for next week will be to observe the testing of floors. The bus
connection mateline work for the floors has been put on hold.
3.1.2. Time Study
The observations were taken on the 8th, 7th and 6th floors. Time study
was done on the previous two floors and it was found that the time taken for each
module closely corresponds to the time studies of previous floors already
finished. Moreover the worker completed each floor within the time frame i.e. 3
days and then moved on to the next floor. No time study was done for floor 6 as
the worker was dealing with only the unfinished work. Future time studies will be
conducted on the floors above the 11th to check for consistency of the
3.1.3. Worker Feedback
The foreman expressed concerns when asked about the bus connection
work. According to the foreman there is a hold on the work due to water damage
on the lower floors. The foreman was disappointed that there was no decision
being made on the bus connection mateline work.
The plumbing work started last week and has been going on smoothly.
Temporary Storm pipe risers were installed upto the 12th floor from floor 8 and
upwards. The actual storm pipes will be installed later on. The Steamfitters, on
other hand, were installing with risers on the 10th 11th and 12th floors,
particularly the matelines that weren’t connected previously. The work was
mainly done in the H6, P7, F6 and G7 mods.
Steam fitters will be moving up on the higher floors as the work goes on
next week. In addition they will be installing the hot water cables inside the mods
to places where the PTAC units will be installed and testing it later in the next
week. In addition a stepbystep photo documentation of the Steamfitting
mateline work was also done.
In detail photo documentation for the storm pipe matelines was not
possible due to poor light and less working space.
3.2.2. Time Study
22.214.171.124. Steampipe Mateline Work
The average time to install the risers was 715 minutes.
This varying nature was due to the fact that some matelines were
easy to install whereas some required up to 2 trips to install. The
variation also included the time taken to cut a pipe to the required
Some of the matelines required up to 2 trips between
floors to be installed. The first trip was to install the risers on the
lower floor. The next trip was to secure the connection after the
necessary adjustments were made.
The number of samples for which this average time was
calculated was 10. The workers usually divided their work where
one would install the pipes and move on to the next job, whereas
the other secured the connections and also connected other
As the work goes on more samples will be taken to further
calculate/update the mateline work time.
126.96.36.199. Storm Pipe Mateline Work
As of this week temporary storm pipes were being installed
from the 8th floor and upwards up to the 13th floor. The riser work
took about 4045 minutes to be completed. There were 2 workers
working on the mateline. One was usually one floor above where
the connection was being made whereas the other worker
connected the mateline on the lower floor. Only 2 samples have
been taken as of yet as the workers were moving around. The
timings were taken for risers between 9th to 10th and 10th to 11th
The work did not call for cutting of the pipes as it was found
that most of the factory provided pipes matched the riser length.
3.2.3. Isolated Incidents
188.8.131.52. Storm Pipes:
Some of the pipes were missing on the lower floors i.e 4,3
Moreover the pipes between the 7th and 8th floors were
way off [Item 10: Misaligned Storm Pipes]
Also many of the steel frames were in the way of the
workers which increased the time taken to install the risers. Some
of the frames were cut and removed.
The workers had to deal with tight spots, particularly in
mods 33 and 35. [Item 11: Tight Spot for Steam Pipe] Other than
this there were no major incidents to note.
3.2.4. Worker Feedback
184.108.40.206. Storm Pipes
The workers were frustrated by the location of the storm
pipes. According to them instead of being installed on the opposite
wall the pipes could have been placed on the side wall so that it
would have been easy for them to work. Moreover since there was
no solid platform to work upon plus steel frames in the way, the
workers were thus worried about the time it will take to complete
The workers seemed disappointed at the fact that they
were not provided with long pipes to do the matelines. According
to them the use of short pipes involves the use of more couplings
[Item 12: Detail of Unnecessary Couplings], which might lead to
leaks in addition to being time wasting and expensive. They
suggested that they could easily and swiftly work with longer pipes
as they do not have to look for pipes for the required length,
instead they could cut as per requirement saving time and money.
Moreover one of the PTAC cables in the 10th floor Unit A5 Mod
1002 was missing which could result in delay in the testing of the
In the past week, carpenters have finished wall and ceiling
matelines on floors 12, 11, and 10. Those three floors already have
fastened floor matelines. Carpenters are currently working on the 9th floor
matelines, and will continue down from there. The completed floors have
some missing wall/ ceiling matelines (of which the sides of the matelines
are observed to be very close to one another <1.5”). The workers have
informed us that those are inticipated to have expansion joints. Those,
and covering plumbing/ electrical mateline will be completed at a later
3.3.2. Time Study
Time studies are hard for the carpentry trade because of the
variable nature of the matelines. Some take as little as 5 minutes, some
take as long as an entire day. So far there are more than 6 distinct types
of carpentry matelines. A few of these are already documented and can
be found in this week’s draft of the Mateline Procedure document.
3.3.3. Recurring Incidents
220.127.116.11. Provided Wall Frames Not Being Utilized
It was observed that the wall framing that is factory
provided [Item 6: Provided Wall Framing] is not being utilized by
carpenters. When asked, the carpenters responded that their
foreman instructed them to disregard them and instead build their
own framing. In addition, the carpenters explained that the
provided framing would not be square and when installed would
not yield the correct dimensions for a door frame. It was observed
that none of the frames were attempted to be used. Walls
constructed from scratch were observed. These were the most
time consuming carpentry matelines.
18.104.22.168. Uneven Holes Around Steel Plates
It was observed that in many of the places surrounding the
steel plates connecting mods, the carpentry installed to cover it
was not flush. This was due to crude holes being cut by steel
workers for access to the steel beams..
Examples of holes cut by steelers on the 9th floor: Item 1:
Steel Plate ex. 1, Item 2: Steel Plate ex. 2, Item 3: Steel Plate ex.
As a result of crude holes, the installed sheetrock and
versaroc is not square; examples shown in Item 4: NonSquare
Wall Mateline and Item 5: NonSquare Floor Mateline.
The installation of sprinkler matelines on the 9th floor was
completed on Friday, 18th and the system was tested a second time after
a minor leak in the stand pipe. No leaks were found in the second test
and the floor was okayed.
A new set of two workers started with the 10th floor mateline
connections. However the connections were still not complete on floor 6
due to the presence of mechanical pipes in the way of sprinklers. The
problem was noted and action is soon about to take place in the coming
week. Once the 6th floor is complete the workers will test the sprinkler
system from floor 2 to 10 with water at 50 psi for an hour to check for
leaks. The test is scheduled to take place next week.
The riser connections for the drain pipe were started on Tuesday.
The risers have been installed to the 13th floor from floor 9 and
upwards.Similar tests will take place on the higher floors. The workers
conducted a pressure test on the stand pipes upto the 15th floor.
3.4.2. Time Study
Time studies were conducted for floor 9 and the drain pipe riser
work. The time taken for matelines from the corridor pipe to the module
pipe was similar as on the lower floors: 57 minutes for each mateline.
The matelines in front of the staircases i.e. electrical room matelines took
about 15 minutes because the pipes were 1 ¼” and grooved. Since the
workers’ machine did not groove 1” pipes they had to thread it instead,
thus taking 10 minutes to complete the work.
There was an improvement on the other hand in the module H6
(between 09330934). The mateline being in a tight spot was difficult to
get to on the 8th floor and thus took about an hour to complete. But as the
worker were aware of that fact they proceeded with a plan and completed
the work within 45 minutes.
The drain pipe riser matelines took about 10 minutes to be
installed. The number of samples for which this time was calculated was 3
out of 4 matelines.
3.4.3. Isolated Incidents
22.214.171.124. Grooved 1” Pipes
As the workers’ machines does not groove 1” pipes they
had to thread the whole section of the pipe i.e the connecting pipe
from the corridor and the electrical room pipe. It was found that the
upper floors too had grooved pipes and thus to avoid time wasting
in threading the pipes future mods maybe preinstalled with
126.96.36.199. Excessive Paint
Some of the standpipes had excessive paint, which had to
be sanded off in order for a connection to be made [Item 13:
Excessive Paint on Standpipe]
188.8.131.52. Misalignment of Holes and Pipes on 13th Floor
One of the drain pipe riser hole was misaligned with the
pipe. The worker managed to install the riser without drilling a
184.108.40.206. Elbow Pipe out of wall
One elbow pipe on the 9th floor east of the leasing office
room (Mod 0913) was way out than the required amount. The
workers still installed the mateline. According to him a wrong
nipple was used. Instead of a 3” a closed nipple should have been
used.Item 7: Sprinkler Elbow Pipe
220.127.116.11. Support Failure of Sprinkler Riser
The standpipes were pressure tested on Wednesday to
check for leaks. The test was supposed to take place at 300 psi
but the worker wanted to increase the pressure in steps to avoid
bursting of pipes. The first test was done at 150 psi and there
were no leaks to be found. But as the pressure was increased the
pipe going through staircase 2 sunk by 4” due to the weight of the
pipe plus water. Item 8: Sprinkler Riser Failure and Item 9:
Sprinkler Riser Failure Detail.
Further damage was prevented due to the use of riser
clamps on certain floors installed by the workers. A meeting took
place with Bill, the project manager from Turner Construction Co.
There was talk of starting at the 15th floor, disconnecting the riser,
moving it up to the correct height, and repeating that process joint
by joint all the way to the basement.There was some investigation
as to whether or not damage was done to Barclay Center
3.4.4. Worker Feedback
The workers expressed concerns over welding of the sprinkler
pipes. According to him welding may cause leaks as sometimes welding
Another major concern was the going down of the standpipe
through the staircase 2. According to one of the workers the use of
compressed wood to support the pipe was not sufficient as the pipe was
too heavy for the wood floor. His suggestion was to form a square cement
unit around the pipe to support the added weight. The worker seemed
frustrated and worried that this would hurt somebody in the future.
The modules continue to go up, they will be delaying for a few
days to jump the crane next week.
4.2.1. Progress: None
4.3. Washer/ Dryer
4.3.1. Progress: None
5. Qualitative and Empirical Data
The trend holds that after at least a week of working on mateline work,
productivity sees a large boost. Idling and conversations are more common when
different trades are working on the same floor as workers will stop for a quick
chat. Workers are able to chat while being productive within their trades.
6. Other Issues or Events: none
7. Conclusions and Recommendations
The suggestions of workers for recurring incidents seem to hold value. The
sprinkler riser failure this week was a direct result of the riser not having adequate
bracing. The workers we had been observing made this suggestion at the very
When speaking with the carpenters about why they did not choose to use the
provided built framing, the question was asked what would help them make the frames
useful. The workers suggested a plan labeled for them with the frame numbers on a floor
plan. If such a plan exists, or if there is a system in place for that, the workers know
nothing about it and instead are building their own frames. In addition there seems to be
no forward looking as far as materials go. They will wait to run out of sheetrock/ versaroc
before ordering more as opposed to making an educated guess at the beginning
whether or not they will need more.
8. References: none
9.1. Item 1: Steel Plate ex. 1
Shown above is a steel plate connecting two mods on the wall in the 9th floor
corridor. The hole cut to access the beams was crudely done. [Back to Uneven Holes
Around Steel Plates]
9.2. Item 2: Steel Plate ex. 2
Shown above is a steel plate connecting two mods on the floor between mods 0932 and
0930. The floor was crudely cut, and not supported after. As a result, the left half of the
hole has broken when someone stepped on it. [Back to Uneven Holes Around Steel
9.3. Item 3: Steel Plate ex. 3
Shown above is a steel plate connecting two mods located in the cooridor of the 9th
floor. The sheetrock was crudely cut to access the beam. [Back to Uneven Holes
Around Steel Plates]
9.4. Item 4: NonSquare Wall Mateline
Shown above is the result of a crudely cut steel frame hole. This mateline is located over
a beam, in the corridor wall of the 10th floor.The sheetrock that was installed to cover the
hole does not align because of the asymmetric hole cut by steel workers. In this
instance, the sheetrock was fit to the lower corner, outlined in black dotted line. The
opposite side had a 1.5” gap, outlined in red dotted line. [Back to Uneven Holes Around
9.5. Item 5: NonSquare Floor Mateline
Shown above is the result of a crudely cut steel frame hole. This mateline is
located on the floor of the mechanical room on the 10th floor connecting mods 1023 and
the adjacent mod to the west. The versaroc fitting that the carpenter installed is not
square because of the crude hole cut to install steel plate underneath. [Back to Uneven
Holes Around Steel Plates]
9.6. Item 6: Provided Wall Framing
Shown above is the factory provided wall framing provided in the 9th floor in mod
0909. [Back to Provided Wall Frames Not Being Utilized]
9.7. Item 7: Sprinkler Elbow Pipe
Shown above is a Sprinkler Elbow located east of the leasing office (Mod 0913).
The red dotted line shows where the soffit will be built, showing that the elbow
will not fit within the existing soffit. Worker completed the mateline and left the
elbow. [Back to Elbow Pipe out of wall]
9.8. Item 8: Sprinkler Riser Failure
Shown above is the base of the sprinkler riser in staircase 2 on the second floor.
While workers were increasing pressure in the riser, the weight of the riser
caused a failure. As a result, the clamps broke the sheetrock supporting it. [Back
to Support Failure of Sprinkler Riser]
9.9. Item 9: Sprinkler Riser Failure Detail
Shown above is the Sprinkler Riser where it passes through the 2nd
floor ceiling in staircase 2. The red line shows how far the riser
disconnected from the cement. [Back to Support Failure of Sprinkler
9.10. Item 10: Misaligned Storm Pipes
Shown above are misaligned Storm Pipes between floors 7 and 8. [Back to
9.11. Item 11: Tight Spot for Steam Pipe
Shown above is a steampipe mateline that is hard for workers to work with
located in mod 0834 unit H.6. It was observed that this tight spot is consistent on
all floors. [Back to Steamfitters]
9.12. Item 12: Detail of Unnecessary Couplings
Shown above are couplings that the workers have deemed unnecessary. This
particular coupling is located on the 8th floor mod 33 unit H.6. [Back to
9.13. Item 13: Excessive Paint on Standpipe
Excessive paint causes and imperfect coupling joint and thus can lead to leaks.
According to the worker the pipe should be painted at a distance of about 2” from
the groove. [Back to Excessive Paint]