Ezzat Grout
Manager, Techncial Support
Kaust, Thuwal. KSA



With reference to the meeting held in Al-Khobar on 24 July 2013, and your review comment No. 1 on 50% detailed design of KAUST Perimeter Security Systems (KPSS) Project, we bring your attention to the Project Proposal document, where two arrangements have been mentioned and the one adopted in the 50% DD is the one which was preferred not only in the project proposal but also preferred by the project designer based on the following;
 
1.	The primary objective behind the design of this perimeter security system is to stop any motorized threats by creating physical obstructions. Even though the wall has anti-climb spikes to stop humans climbing the wall but humans intrusion is considered secondary and not the first major concern in the design of this perimeter system.
2.	The response times don’t matter much if the IDAS were situated before or after, above or below, far or near the wall.
3.	The crash rated wall provides a first line of defence against mechanized/ motorized threats. To further stop the mechanized threats a ditch right behind the wall provides a second physical and effective line of defence and also provides an element of surprise. It also stops the subsequent threats after/ if the first vehicle damages the wall without providing any space to recoup. Any extra space between the wall and the ditch only provides more options to the intruders.
4.	Since there are access ramps between the ditch and the maintenance road, if the ditch is far away from the wall, intruders will have enough space to find the ramps and cross the ditch with vehicles.
5.	When the vehicles are stopped effectively, the intruders will have to move on foot, where the IDAS will detect them and the existing fence will create a delay in their progress.
6.	Every element of the KPSS requires a certain space and width according to product specs, functional requirements, general safety principles, constructability and HCIS requirements. Adopted arrangement requires a minimum of 27 meters between the new wall and the old fence. The attached sketch shows that by changing the arrangement the distances will increase to 35 or more meters and 70% of the perimeter does not have this much space. The Northern boundary does not provide any more than 25-27 meters to arrange all the elements of the KPSS. The attached sketch can only be adopted at the eastern boundary. In the same way, the southern boundary also does not have enough corridor widths.

7.	In case IDAS is situated near the wall or on top of the wall, with impact from a motorized threat, the wall will come down with IDAS or fall on top of IDAS, and hence, two lines of defence will become ineffective by a single blow. The ramps in the ditch will allow the intruders to advance without much obstruction.
8.	With the adopted arrangement, the existing patrol road could be used as a maintenance road for the new system. This will reduce the width of security systems corridor and make more land available where possible.
9.	In case the ditch is next to a road, without any obstructions in between, there are chances of accidents. Safety shall require 15 kilo meter long traffic barriers which are not included in the scope of work.
10.	Keeping all of the above in consideration the first arrangement mentioned in the Project proposal was adopted and the second option which was included as a suggestion was dropped after careful studies. Now that 50% design has been completed any change in the basic arrangements in the security corridor shall add approximately 60 days to project completion dates. The extra work shall require:
a.	Redesign of Site layout of the perimeter fence (shift the perimeter fence and ditch to revised location, changing the coordinates and control points)
b.	Redesign of the perimeter fence profile.
c.	Redesign of the grading of the site.
d.	Redesign of FED Cable layout, SSD 13 lighting, camera locations thereby redesign the security package.
e.	Redesign/ Re-evaluate the width requirements of the culverts on flood control channels
 
In light of the above we maintain that the adopted arrangement of the security corridor is the best option which optimizes the security requirements in consideration with available land conditions, interfaces and existing construction.

Should you have any questions, please contact Fahad A. Al-Balawi, Senior Project Engineer at Tel No. +966 2 422-4393.
